IGCSE/GCSE/O & A Level/IB/University Student Forum
Qualification => Subject Doubts => IGCSE/ GCSE => Sciences => Topic started by: Muho on June 01, 2009, 09:24:42 pm
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It's nonsense. Guys wth it takes like 12 hours max. for all the exams to be over in the world I think. 24 hours is too much o.O Anyway just wanted to ask how was it, don't want any answers, like "easy" or "hard" because mine kinda sucked. xD no that topic Q80boy did won't work because a topic attracts more attention. ^^
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I gave my paper and it was terrible .. just like ihavent studied for it at all ... I totally screwd in my paper ...
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Bleh I agree xD some parts were easy but that last page, and the phosphate messed me up >.< around 10 marks off me already =p
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exactlly ... well i left those pages blank .. because i couldnt even write a thing .. the last page and the Mysterious Element T ..I left them blank
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exactlly ... well i left those pages blank .. because i couldnt even write a thing .. the last page and the Mysterious Element T ..I left them blank
No worries. I heard the grade boundaries go down low on this one. Might just get away with an A ^^ and hey, you can still change the tides. Paper 1.
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yep ... Paper 1 is our ONLY HOPE .. I better not screw in it .. because it is the last paper that will backup My Grades .
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i agree...don't worry u gyz!
but im desperate...WHICH TWO SPCIAL METALS REACT WID COLD WATER AND WHICH ONE isnt OXIDISES BY CARBON?!
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i agree...don't worry u gyz!
but im desperate...WHICH TWO SPCIAL METALS REACT WID COLD WATER AND WHICH ONE isnt OXIDISES BY CARBON?!
haha only if i remembered xD i kinda forgot. and if anyone accuses him for asking this question, i'm gonna be mad. I pretty much doubt that there is any paper 3 chemistry exam going on right now. It's over. the 24 hour rule is ridiculous!!
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go tell that to cie.
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:S mines was ok
not the BEST though...
paper 6 way WAYYY better!!!
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go tell that to cie.
bleh, he didn't get any answers anyway. cba.
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ughness...can sumone pls answer my question!? yes i am bbeing annoying..
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Chemistry was very complicated.....the style of the questions have changed....look at the electrolyses question....they put them in a table instead of plotting a diagram and we have to answer some questions...i'm not saying this question was hard...it's just different.....as well as some other questions.....why did they put a biology question in this exam?.....that's about five marks for these 2 questions......and i screwed up the last page...with the moles...so thats another 10 marks off!....and the phosphate question:P.....hope the curve goes down just like many people say
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Chemistry was very complicated.....the style of the questions have changed....look at the electrolyses question....they put them in a table instead of plotting a diagram and we have to answer some questions...i'm not saying this question was hard...it's just different.....as well as some other questions.....why did they put a biology question in this exam?.....that's about five marks for these 2 questions......and i screwed up the last page...with the moles...so thats another 10 marks off!....and the phosphate question:P.....hope the curve goes down just like many people say
that one saved my day. =p 8 marks guaranteed xD the electrolysis one. the moles question was very unusual. phosphate looked like a different language to me. i really wonder who got a reasonable answer to get one mark for that one, not even three =/
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i'm sure everyone is garanteed 8 marks in this exam...:P...but what about the rest?......i calculated my answers that im 100% sure they're right.........it's out of 80...so my mark was 49/80...so thats like 60% or something.....and now that the curve is low...i think i might get an A if i do good in paper 1 ;D
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the ppr was f9 for me except the phosphate thingy....n maybe i must hv made sum other mistakes but dont realli remember.....neways its OVER n dats wat the reality is...wohoooo...no mor chemistry!!!!
n i guess p1 is nt dat hard...i mean nly selectin answers frm the list given....so u cn *inny meeny myna mo* the answers....lolzz....if ur nt gettin them .......atleast it wont go blank....n who knos ur *inny meeny mynamo* answers r rite.... :D :D :D
lollzzz....chill out guys!!!
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I screwed up mine too!
9 questions instead of ordinary set of 7! The parts i am not sure that they are correct or not are:
1)T element- i wrote potassium as it is more reactive.
2)show that the reaction is exothermic- i added first 2 subtracted the value from the last one
3)test other than indicator to show that acid group is present- left blank
4) last page aluminum stuff - my equation was
Al4C3 + 12 H2O --> 4Al(OH)3 +3CH4
rest every thing was correct except for 2 marks in electrolysis and 1 mark for property of ionic compounds.
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I screwed up mine too!
9 questions instead of ordinary set of 7! The parts i am not sure that they are correct or not are:
1)T element- i wrote potassium as it is more reactive.
2)show that the reaction is exothermic- i added first 2 subtracted the value from the last one
3)test other than indicator to show that acid group is present- left blank
4) last page aluminum stuff - my equation was
Al4C3 + 12 H2O --> 4Al(OH)3 +3CH4
rest every thing was correct except for 2 marks in electrolysis and 1 mark for property of ionic compounds.
number 4 is correct. xD but anyway i'm not sure, and can't bother myself with this anymore. there's an exam for me tomorrow, english language for edexcel, and i must revise on that. One last chance. Paper 1; use it! good luck everyone *goes off*
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for the indicator question..i wrote pH meter........i know it's wrong..but at least i wrote something...who knows..i might get it right anyway.......and for the Aluminium question i didnt balance it...so i think i got 1 for a non balanced equation instead of 2...
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i wrote for the acid thingy, add drops of an alkali, and if acid is present a reaction will take place
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what about the chlorophyll question?....the first one where it says *how can you show that this green solution contains chlorophyll*?...and the second one that has 3 marks!...*expain the role of chlorophyll*?...
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how was the graph on the ammonia?
inverse rigth?
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how was the graph on the ammonia?
inverse rigth?
yea it starts high and decreases as u go along
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what about the chlorophyll question?....the first one where it says *how can you show that this green solution contains chlorophyll*?...and the second one that has 3 marks!...*expain the role of chlorophyll*?...
u add iodine it turns black, i wrote stuff like photosynthesis, and gives it its colour, and absorbs light etc, last time i read bout chlorophyll was years ago lol
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Dudes i found chem pretty easy :D
it wasnt awesome
bt it wasnt bad
i was expecting worse
especially after how easy 2008 papers were
for da chlorophyll i took a guess and wrote you compare da colour of chlorophyll to da colours of the constituents on da chromatography paper
if it is a match then chlorophyll is present
although i dnt expect marx for dat answer
and for da acid 1 i wrote you add a metal and hydrogen gas is given out
ok its june 2nd so i think its okay to post this ryt?
and yeah inverse
and chlorophyll is a catalyst for photosynthesis
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if you dissolev chlorophyll in ethanol, doesnt its color go away ?
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im not sure if it does lol
all i know is chlorophyll is a green pigment
and dat ethnol removes starch
i think im not even sure about that
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yeah I think it dus.... it decolourises it ....i think ..:P
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no it doesn't remove the start ,, i remember in one of the tests we had to learn, one of the steps was to i dono boil or something the leaf in ethanol to dissolve the chlorophyll and it would turn it white ?
so cant that be used as a test to see if chlorophyll is there
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"for the indicator question..i wrote pH meter........i know it's wrong..but at least i wrote something...who knows..i might get it right anyway.......and for the Aluminium question i didnt balance it...so i think i got 1 for a non balanced equation instead of 2..."
dude.. dip a pH meter is 100% correct..!
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Ok guys
i guess 24 hours are up...
oh and mods are not here aswell so when they wake up 24 h will be over...
need answers...specifically of the follofwing question....
1)how would u explain the the sample contained cholorophyll?( iw rote carry another exp and then calculate the distance of the two dots.as pure cholorophyy wil make only one spt and the other one 2-3 so see the distance in which the dots appear and compare)
2) metal T
i wrote formula is t3(po4)2 because it is an insoulble salt(ionic) and gruop 1 metals make soluble salts thus group 2 is there
thus t3po42.,......hope this is correct?
3) the graph of ammnoina
it was inverse right and explanation was that as temp increases the endo one increases...
4) the question in which we had to show that the reacrion is exo...
the answer was like -30 or something...right?
5) the 2 gropus in the lactic one was alkanoic and alcohol...or alcohol or carboxylic?
6) the 2 advantage s of PLA was it can be recycled and it doesnt give fumes right???
need answers of these 6 question.....
plus its 4 am my paper was done 20 hours before
so i think mod can compensate 4 hours.:D
need answers..
thanks in advance
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"for the indicator question..i wrote pH meter........i know it's wrong..but at least i wrote something...who knows..i might get it right anyway.......and for the Aluminium question i didnt balance it...so i think i got 1 for a non balanced equation instead of 2..."
dude.. dip a pH meter is 100% correct..!
Its 100% wrong PH meter is an indicator .they said how would you test if the 2 something is acidic without an indicator ....test: add any metal sodium for example ...results: hydrogen gas revolves....-rep me if am wrong and +rep me if am right :D
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youre write...
and i got t3po4.
not t3po42
i used the n = c x V
and since c was constant, n is proportional to v
something like that.
i got t3po4
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how was the graph on the ammonia?
inverse rigth?
yea it starts high and decreases as u go along
rate of reaction increases as temp. increases so the graph will be high to low ! and at a certain level constant
Can't we interpret this idea ????
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T3PO4???
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the ppr was f9 for me except the phosphate thingy....n maybe i must hv made sum other mistakes but dont realli remember.....neways its OVER n dats wat the reality is...wohoooo...no mor chemistry!!!!
n i guess p1 is nt dat hard...i mean nly selectin answers frm the list given....so u cn *inny meeny myna mo* the answers....lolzz....if ur nt gettin them .......atleast it wont go blank....n who knos ur *inny meeny mynamo* answers r rite.... :D :D :D
lollzzz....chill out guys!!!
It's actually nothing much. JUst look at how many times more the solution and simplify he formulae. My answer T(PO4)3
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yes!!
i wrote T3PO4
although i m not sure
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Ok guys
i guess 24 hours are up...
oh and mods are not here aswell so when they wake up 24 h will be over...
need answers...specifically of the follofwing question....
1)how would u explain the the sample contained cholorophyll?( iw rote carry another exp and then calculate the distance of the two dots.as pure cholorophyy wil make only one spt and the other one 2-3 so see the distance in which the dots appear and compare)
2) metal T
i wrote formula is t3(po4)2 because it is an insoulble salt(ionic) and gruop 1 metals make soluble salts thus group 2 is there
thus t3po42.,......hope this is correct?
3) the graph of ammnoina
it was inverse right and explanation was that as temp increases the endo one increases...
4) the question in which we had to show that the reacrion is exo...
the answer was like -30 or something...right?
5) the 2 gropus in the lactic one was alkanoic and alcohol...or alcohol or carboxylic?
6) the 2 advantage s of PLA was it can be recycled and it doesnt give fumes right???
need answers of these 6 question.....
plus its 4 am my paper was done 20 hours before
so i think mod can compensate 4 hours.:D
need answers..
thanks in advance
For ur 6th one, i did write its recyclable, or biodegradable, but HOW DID U GET THAT IT DOESNT GIVE OFF FUMES??? Where did u get that from?
I wrote thats its easily obtainable, since it comes from corn starch and not petroleum.
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YEAY! :) i got that toooo
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my questions:
1) why do u wash the precipitate (i sed to remove impurities, dunno it its rite)
2) why do u put it in the oven ( i sed to get it in molten state)
3) exo thingi, wt did u guys get?
4) the source of nitrogen?
5) the adv of PLA
my chorophyll and Tphospate thing is rong :(
is pH meter correct By the way? i wrote that too :(
the first question was a drawing of chromatography experiment rite?
if 10-15 marks r gone, is it still an A/A*?
jeez, now this is making me depressed :(
lets discuss now guys, its time already!
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What else?? POST SOME QUESTIONS!!!
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man I messed up the first two parts of the first question... for the separation I initially drew a chromatography diagram and then rubbed it out :'( and then drew fractional distillation. i hope they allow that; it didnt specify that the pigments have the same boiling point
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my questions:
1) why do u wash the precipitate (i sed to remove impurities, dunno it its rite)
2) why do u put it in the oven ( i sed to get it in molten state)
3) exo thingi, wt did u guys get?
4) the source of nitrogen?
5) the adv of PLA
3) prove its an acid (i said use ph Meter)
my chorophyll and Tphospate thing is rong :(
the first question was a drawing of chromatography experiment rite?
if 10-15 marks r gone, is it still an A/A*?
jeez, now this is making me depressed :(
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ppl cn we pls discuss :(
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i guessed, said it would contain the p043- ion. Should be one of the three marks :-\
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Here r the answers susman:
1) 4 the first question we carry out the same experiment again 4 chlorophyll pure sample and measure the Rf value and then carry the chromatography of the green solution and also measure the Rf values 4 the spots. see which Rf value matches with chlorophyll or is at the same height as the pure chlorophyll dot.
2) i did metal phosphate like u susman T3(PO4)2 but i had a different xplanation.
3)the graph of ammonia is inverse
4)in the exo thingy i added the first 2 bond energies and then subtracted (2*last bond energy) from it
5)groups in lactic acid are alcohol and carboxylic acid.and the compound which contains this type was fats or esters
6)in the PLA i wrote its biodegradable and doesnt give out toxic fumes like petrol
WAT IS THAT INDICATOR question u r discussing?
if it is that ques that has 1 mark then PH meter AND indicator are correct ;)
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"for the indicator question..i wrote pH meter........i know it's wrong..but at least i wrote something...who knows..i might get it right anyway.......and for the Aluminium question i didnt balance it...so i think i got 1 for a non balanced equation instead of 2..."
dude.. dip a pH meter is 100% correct..!
Its 100% wrong PH meter is an indicator .they said how would you test if the 2 something is acidic without an indicator ....test: add any metal sodium for example ...results: hydrogen gas revolves....-rep me if am wrong and +rep me if am right :D
Same answer 555
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No indicator is wrong
It was stated in the question " Other than an indicator "
So I guess a test will be fair
and for the exothermic thing
Guys you don't do that multiplication thing
I actually studied this particularly for the IGCSE Course
You add the bonds for H---H and F----F that are stated
You add them and the no. will be higher than the H----F in the table, so if it is higher than its exothermic
I studied that from an IGCSE book specially designed by Cambridge
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Damn......i wrote metal T was lead so it becomes Lead Phosphate!!>>>>>>>>STRANGE RIGHT
Also i did describe how it formed :-X
Hope I did Well
aquarian93@ how come u wrote pH meter and he said beside using indicator!!
To measure pH u must add universal indicator right?!!
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i thought u were talking abt another ques
if it is the test 4 organic acid then ya indicator is wrong, i wrote adding a carbonate, it will give effervacences that will turm lime water milky
i thought u r talking abt another ques, the one were they want us to differentiate between the strong and weak acid
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what about the chlorophyll question?....the first one where it says *how can you show that this green solution contains chlorophyll*?...and the second one that has 3 marks!...*expain the role of chlorophyll*?...
u add iodine it turns black, i wrote stuff like photosynthesis, and gives it its colour, and absorbs light etc, last time i read bout chlorophyll was years ago lol
for the chlorophyll u were supposed 2 do reference chromotography nt an idone test.
its chem nt bio plus chlorophyll dsnt hve starch thus dsnt turn iodine into anytin' !!
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1-WASHING THE PRECIPtate to remove impurities and get pure salt
2-heating in an oven to evaporate water and drying the salt
3-t3po4, because 18.0cm3 of T completely reacted with 6.0cm3 of po4 (from graph) there fore 18 is three times 6 .................
4-last page
i-the emperical formulae was Mg3N2
ii-silicon was limiting reagent
iii-0.08 moles
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he said beside using indicator
so u should add a carbonate like calcium carbonate bubble the gas produced through lime water turns milky white
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plus chlorophyll dsnt hve starch thus dsnt turn iodine into anytin' !!0
exactly LOOOL
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for the bond energies they were H----H and F----F and 2H----F
we add the bond energies for H----H and F----F
then we multiply 2 by H----F
then we subtract (H----H + F----F)- (2*H---F)
the ans will be negative
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For the pure chlorophyll sample...how to check if grass contained chlorophyll
i wrote:"Apply pure sample of chlorophyll on chromatogram paper and place in solvent,allow to rise and then match the dyes with tht of grass sample...!! Is tht correct?!!!!
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"for the indicator question..i wrote pH meter........i know it's wrong..but at least i wrote something...who knows..i might get it right anyway.......and for the Aluminium question i didnt balance it...so i think i got 1 for a non balanced equation instead of 2..."
dude.. dip a pH meter is 100% correct..!
Its 100% wrong PH meter is an indicator .they said how would you test if the 2 something is acidic without an indicator ....test: add any metal sodium for example ...results: hydrogen gas revolves....-rep me if am wrong and +rep me if am right :D
I ADDED A CARBONATE: GAS GIVEN OFF WHEN PASSED THROUGH LIME WATER TURNS IT MILKY...EH?
AND FOR THE BOND ENERGY ITS PRODUCT ENERGY _ REACTANT ENERGIES NT DA OPPOSITE
THUS POSITIVE ANSWER 'N RXN IS EXOTHERMIC!!
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For the pure chlorophyll sample...how to check if grass contained chlorophyll
i wrote:"Apply pure sample of chlorophyll on chromatogram paper and place in solvent,allow to rise and then match the dyes with tht of grass sample...!! Is tht correct?!!!!
its refrence chromotography so urs is soo close 'n yeh may b correct
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"for the indicator question..i wrote pH meter........i know it's wrong..but at least i wrote something...who knows..i might get it right anyway.......and for the Aluminium question i didnt balance it...so i think i got 1 for a non balanced equation instead of 2..."
dude.. dip a pH meter is 100% correct..!
Its 100% wrong PH meter is an indicator .they said how would you test if the 2 something is acidic without an indicator ....test: add any metal sodium for example ...results: hydrogen gas revolves....-rep me if am wrong and +rep me if am right :D
I ADDED A CARBONATE: GAS GIVEN OFF WHEN PASSED THROUGH LIME WATER TURNS IT MILKY...EH?
AND FOR THE BOND ENERGY ITS PRODUCT ENERGY _ REACTANT ENERGIES NT DA OPPOSITE
THUS POSITIVE ANSWER 'N RXN IS EXOTHERMIC!!
negative answer is exothermic and I also said carbonate- if u said metal or metal oxide it would also react with water hence not correct ;)
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1-WASHING THE PRECIPtate to remove impurities and get pure salt
2-heating in an oven to evaporate water and drying the salt
3-t3po4, because 18.0cm3 of T completely reacted with 6.0cm3 of po4 (from graph) there fore 18 is three times 6 .................
4-last page
i-the emperical formulae was Mg3N2
ii-silicon was limiting reagent
iii-0.08 moles
yup all those r rit i tink...although i got da MG1.5N1
i knw u cnt gt a decimal ....am sooo stupidish :(
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yea negative ans is exo
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we should subtract (energy taken in during bond breaking)- (energy released during bond formation)
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he said beside using indicator
so u should add a carbonate like calcium carbonate bubble the gas produced through lime water turns milky white
i wrote exactly the same thing!!!!
wat was ans 4 da chlorophyll thing
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How cute! 24 hours are not over yet sorry.
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Can you people just stop ?
What are you guys gaining how can you be 100% sure that your answers are right , if you have questions go to your teachers , instead of wasting time trying to see if you got things right study for physics who knows it might be just as fd up as chemistry .
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There is no benefit to know the correct answers, anyway the 24 HOURS are not over.
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Ok go on now..Hope you all did good despite being a hard exam
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Go on now, I hope everybody did good in the exam
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Thanks..... sweetsh
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For the pure chlorophyll sample...how to check if grass contained chlorophyll
i wrote:"Apply pure sample of chlorophyll on chromatogram paper and place in solvent,allow to rise and then match the dyes with tht of grass sample...!! Is tht correct?!!!!
i wrote the exact same thing
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I think you should write something about comparing
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damn... the test was definitely hard... i thought i did ok, until i read the answers people wrote here :(
hopefully the curve will be really low though...
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You dont have to be sad, there answers might not be right, I hate that when we are out of the examination hall and they begin answering, I just dont like it, because it wont benefit you at all
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You dont have to be sad, there answers might not be right, I hate that when we are out of the examination hall and they begin answering, I just dont like it, because it wont benefit you at all
exactly what is over is over....gear up fot the next paper
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hey, do you think bio and physics ppr 3 will be this way as well? way different from the past year papers?
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man i really hope the physics is easier... so that if i get an A* ill show it my parents first ;D maybe it'll get their mind off the chemistry mark
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Just to clear the T metal question.....IT CANNOT BE A GROUP ONE metal since it forms a percipitate..the metal is Al3+....answer is TPO4....actual equation Al(NO3)3 + Na3PO4 ? AlPO4 + 3NaNO3...search it on google and see
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what you say is true. but can some1 plz tell me why fractional distillation is wrong for the first question. i had initially drawn a chromatography diagram but rubbed it out. they did not specify that the pigments have the same boiling point; for some reason i assumed they were different. plz answer this
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Just to clear the T metal question.....IT CANNOT BE A GROUP ONE metal since it forms a percipitate..the metal is Al3+....answer is TPO4....actual equation Al(NO3)3 + Na3PO4 ? AlPO4 + 3NaNO3...search it on google and see
if this is true, i put alp04, this will probably the guess of the century!!!!!! :P
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"for the indicator question..i wrote pH meter........i know it's wrong..but at least i wrote something...who knows..i might get it right anyway.......and for the Aluminium question i didnt balance it...so i think i got 1 for a non balanced equation instead of 2..."
dude.. dip a pH meter is 100% correct..!
Its 100% wrong PH meter is an indicator .they said how would you test if the 2 something is acidic without an indicator ....test: add any metal sodium for example ...results: hydrogen gas revolves....-rep me if am wrong and +rep me if am right :D
I ADDED A CARBONATE: GAS GIVEN OFF WHEN PASSED THROUGH LIME WATER TURNS IT MILKY...EH?
AND FOR THE BOND ENERGY ITS PRODUCT ENERGY _ REACTANT ENERGIES NT DA OPPOSITE
THUS POSITIVE ANSWER 'N RXN IS EXOTHERMIC!!
negative answer is exothermic and I also said carbonate- if u said metal or metal oxide it would also react with water hence not correct ;)
The exact question if am not mistaken is "describe a test other than the use of indicator to show that both chemicals belongs to an acidic group <----I don't see no water in the question so the test is by reacting a metal and the result is hydrogen gas revolves am sure of the answer i've discussed the queston with my chemistry teach am definately right :)
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As far as i remembrd dat Aluminium n Carbn compound ws Aluminium Carbonate... Dat T formula i wrote T3(PO4)2... N in dat exo ques i did sum calculatns dan wrote It is an exo because change in temp is in negative n Energy required for bond breakng is less dan energy releasd during bond formation... Limitng reactant ws Si n moles vr 0.08... Abt role of chlorophyl i wrote de trap lyt to cary photosynthesis n de gve colour 2 da plant... N abt PLV advantages i wrote it is cheap as it can be made frm a corn compard 2 petrol n secnd one ws it s biodegrable... Dat circled portion ws Ester group... N it was condensation polymer BECOZ IT CONTAIND DOUBLE BOND...! Mmmm dan dan dan... Ya dat raw material 4 ammonia i wrote Liquid air n 4 hydrogen i wrote Methane(water s also corect).. Use i wrote Fertilizers... Iron ws da catalyst... There ws a ques abt HCl n HF... I wrote HCl ws strong acid n Hf weak... Hope ths is corect... N dat metal ques, electrolysis... I forgot dm... Plz corect me if i gave any wrng ans...
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"for the indicator question..i wrote pH meter........i know it's wrong..but at least i wrote something...who knows..i might get it right anyway.......and for the Aluminium question i didnt balance it...so i think i got 1 for a non balanced equation instead of 2..."
dude.. dip a pH meter is 100% correct..!
Its 100% wrong PH meter is an indicator .they said how would you test if the 2 something is acidic without an indicator ....test: add any metal sodium for example ...results: hydrogen gas revolves....-rep me if am wrong and +rep me if am right :D
I ADDED A CARBONATE: GAS GIVEN OFF WHEN PASSED THROUGH LIME WATER TURNS IT MILKY...EH?
AND FOR THE BOND ENERGY ITS PRODUCT ENERGY _ REACTANT ENERGIES NT DA OPPOSITE
THUS POSITIVE ANSWER 'N RXN IS EXOTHERMIC!!
negative answer is exothermic and I also said carbonate- if u said metal or metal oxide it would also react with water hence not correct ;)
The exact question if am not mistaken is "describe a test other than the use of indicator to show that both chemicals belongs to an acidic group <----I don't see no water in the question so the test is by reacting a metal and the result is hydrogen gas revolves am sure of the answer i've discussed the queston with my chemistry teach am definately right :)
if many things react with it, its not much of a test is it? Either way, if your right, both answers are correct ;)
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hey i thought i can say the ans now,
1)was u had to draw chramatography.
2)explain how u see the cholorophyl in the chramotogram and compare with known spots of chlorophyl, or check and compare Rf value.
3)- write about photosynthesis
- write what does it do (i.e help to trapl sunlight for enegy to combine carbondiaoxide and water)
- write the products of photosynthesis (i.e oxygen and glucose)
then comes tht stuff for elctrolysis.
where an OH is relesed write on the anode the sunstance oxygen (there will be 2 answers with oxygen on the change of anode in this question)
then there was hydrogen and i think copper for change in cathode.
and the last one was aqueous concentrated pottasium bromide.
then i think came the question of periodic table stuff which is easy... i dont think i have to discuss it.
then cam the question of unfamiliar and familiar metals, now this is the only part in the exam i had trouble with. the first 2 question of it i messed up i think (well maybe the frist only the most). the ans for barium was +2, and the answer for the last one i wroet "cuz the same metal is able to react with different substances due to presence of different oxidation states, and they are transitional metals.." questions of haber process came tht ok, the graph was going backwards (down and curved) then explain by refering to exothermic reaction in equilibrium...
then the rest was ok then came, the question how can u say this is exothermic, here u just do those calculations, they even gave u the table for the numbers u need to use. u get answer negative (-530) which means its exothermic reaction.
then came test of sturation, and how water acted as base which was really easy. then cam the question of what happens when lactic acid is heated, the ans: acrylamide acid and water.
then the last page with calculations, first u get the answere for empirical formula as Mg3N2 (i can explain to u how if u want to know).
then the ans for the balencing of the equation:
Al4C3 + 12H2O --->4Al(OH)3 +3CH4
then last question the ans is: silicon is the limiting factor as fulride had 2 times the number of moles of silicon reacted so flourine was in excess.
teh number of moles of silicon fluride was:0.08 moles
now the only question i truly messsed up in was tht phosphate stuff, i must choose a metal tht doesnt dissove, and i must choose a metal tht has higher reactivity than sodium so it could be displaced. there fore i had problems and just wrote T3PO4. but u should also know tht this is not the reson to write. as they gave u tht graph for a reason, so u need to write tht hight of precipitate wise. so if u wrote the reson tht goes somethin like this "i must choose a metal tht doesnt dissove, and i must choose a metal tht has higher reactivity than sodium so it could be displaced", then i feel u messed up...
well ths all correct me if im wrong, alas those were my answeres
lol and guys just write hydrogen chloride had a lower pH than hydrogen fluride. and how to test if those acrylamide stuff had acid, just add metal carbonat and if effevecence was shown due to libbiration of carbon dioxise (which turns lime water milky) then it contained acid group, they wanted an answer which has nothing got to do with an indicator.
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Hey Sneakerz.. Your answers seem pretty decent. I dont know if this is correct or not, but I think Bromine was a limiting factor..
The equation was
Si + 2Br2 ----> SiBr2
If we use the mole equations Moles= mass/Mr.. We rearange it to get 0.16*320.
O.16 because there are two moles of Bromine, and 320 for the Mr of Bromine. Our answer 51.2, therefore more than 25g. We would technically need that amount of Bromine..
My teachers said something along the same line. Dont worry though! It was like 2 marks!
I know people said that we should stop attacking eachother and who is right or wrong..because what is done is DONE! We really should start on physics..but the truth is this is a board to "Discuss Chemistry Paper 3"..So yeah.
On the last page there was also a question..where you had to balance it..and it qas 0.03 moles..and then 0.09 and 0.12 or something..How on earth did u do that. I couldnt balance it for my life..i always had to many oxygens.. :/
Hope you all did well!!!
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yeah I think it dus.... it decolourises it ....i think ..:P
no it only removes chlorophyll from leaves does not decolourise it
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hey ppl sum of u said it is t3po4 ok den u say it is not a metal from group 1 but how can tht be wen u write a formula u exchng da valency n da valency of phosphorous is 3 n it has to be a group 1 metal to becum t3po4
pls reply
n it has to be less reactive metal because it needs only 6cm3 of the other phosphater to react completely n i wrote lithium its less ractive n der is no evidence as far as i noe tht lithium salts are soluble
n for that indicato test i wrote litmus dey only mentioned indicators
n i think ph meters are correct because it is not an indicator n dey did not ask 4 a chemical test
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Go on now, I hope everybody did good in the exam
THANK GOD..... but v hv already discussed da ppr through messages n mails..... HEHE ;)
-
I didn't discuss, I only said it's hard, didn't ask for questions, and didn't answer any because I don't like this.
-
n yes the t nitarate reacts wid wid sodium phosphate t phosphate is da product
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I am so curious to find out the answers so pls answer my following questions:
1 What was the formulae of the metal T?n how to do that
2 What will be (needed to produce/produced by the hydrolysis) of the ester
(where the 2 blanks were given)
3 What was the test to show that both lactic acid and acrylic acid contained the COOH group
I hope i'll get the answers soon
Thanx.
-
I didn't discuss, I only said it's hard, didn't ask for questions, because I don't like this.
OHHHHHHHHHHh........... SSSSOOOOOOORRRRRRRRYYYYY DAn...... :'( :'( :'(
-
I am so curious to find out the answers so pls answer my following questions:
1 What was the formulae of the metal T?n how to do that
2 What will be (needed to produce/produced by the hydrolysis) of the ester
(where the 2 blanks were given)
3 What was the test to show that both lactic acid and acrylic acid contained the COOH group
I hope i'll get the answers soon
Thanx.
-
I am so curious to find out the answers so pls answer my following questions:
1 What was the formulae of the metal T?n how to do that
2 What will be (needed to produce/produced by the hydrolysis) of the ester
(where the 2 blanks were given)
3 What was the test to show that both lactic acid and acrylic acid contained the COOH group
I hope i'll get the answers soon
Thanx.
Some1 ans. me pls
-
I am so curious to find out the answers so pls answer my following questions:
1 What was the formulae of the metal T?n how to do that
2 What will be (needed to produce/produced by the hydrolysis) of the ester
(where the 2 blanks were given)
3 What was the test to show that both lactic acid and acrylic acid contained the COOH group
I hope i'll get the answers soon
Thanx.
1. T3(PO4)2
2. i wrote Alkyl n alcohol
3. litmus ppr. turns BLUE litmus RED
-
I am so curious to find out the answers so pls answer my following questions:
1 What was the formulae of the metal T?n how to do that
2 What will be (needed to produce/produced by the hydrolysis) of the ester
(where the 2 blanks were given)
3 What was the test to show that both lactic acid and acrylic acid contained the COOH group
I hope i'll get the answers soon
Thanx.
1. T3(PO4)2
2. i wrote Alkyl n alcohol
3. litmus ppr. turns BLUE litmus RED
-
I am so curious to find out the answers so pls answer my following questions:
1 What was the formulae of the metal T?n how to do that
2 What will be (needed to produce/produced by the hydrolysis) of the ester
(where the 2 blanks were given)
3 What was the test to show that both lactic acid and acrylic acid contained the COOH group
I hope i'll get the answers soon
Thanx.
i wrote t3po4
hydrolysis of an ester the corresponding alcohol n acid is formed
test i wrote red litmus turns blue
-
I am so curious to find out the answers so pls answer my following questions:
1 What was the formulae of the metal T?n how to do that
2 What will be (needed to produce/produced by the hydrolysis) of the ester
(where the 2 blanks were given)
3 What was the test to show that both lactic acid and acrylic acid contained the COOH group
I hope i'll get the answers soon
Thanx.
1. T3(PO4)2
2. i wrote Alkyl n alcohol
3. litmus ppr. turns BLUE litmus RED
1. T3PO4
2. i wrote an acid group and an alocohol group (im not sure if thats correct thought...)
3. you could have done bromine water test as well (cz on of them had double bond whilst the other dint..)
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yo guz how was da paper!!!!!!!!!!!!!
was it addition or condensation polymerisation????????????
-
yo guz how was da paper!!!!!!!!!!!!!
was it addition or condensation polymerisation????????????
condensatoin because double bond ws present
-
do u take physics!!!!!!!!!!!!!!!!
-
condensation cuz a water molecule is lost at every linkage ;)
-
guys im starting to think there were different papers!
i dont remember the world hydrolysis in the entire paper ???
or maybe i was so stressed that i forgot ???
-
losing like 15 marks :(
-
there must have been different variant papers ?
it sucks to discuss the paper makes u feel how silly mistakes you've made, most because of the limited time
-
i tHINK U R RIGHT EMI.........
DISCUSSION OF DA PAPERS ONLY GIVES U ANXITY AND DEPRESSION!!!!!!!!
THAT IS WAT I HAV OBSERVED
-
any one remember the marks for these Questions ?
1- Q1 & 2 the chlorophyll ones
2- the moles one ( balancing the formula & last one & the limiting reagent one)
3- Metal T
can u tell separate marks for each ?
-
Wait a sec. I think ppl are trying to discuss the same answers to different questions. For the T metal question, how many people got a question where it gives you the volumes of reactant? (namely 6cm3 and 18cm3)
And for the "2 blanks" question, how many people got a question asking which groups the lactic acid contains? Because i wrote Carboxylic acid, and alcohol. And many ppl are saying they wrote "alkyl" and alcohol. I mean.... where did alkyl pop up from? Theres definitely no alkyl group in lactic acid...
My bad. There is an alkyl group, but the question was identify the FUNCTIONAL GROUPS. Alkyls are not functional groups. Only OHs and COOHs are.
-
any one remember the marks for these Questions ?
1- Q1 & 2 the chlorophyll ones
2- the moles one ( balancing the formula & last one & the limiting reagent one)
3- Metal T
can u tell separate marks for each ?
the chlorophyll one had 3 marks
the metal T had 3 marks
balancing was 2 marks and the limiting reagent was 2-3 marks(don't remember)
-
what about the chlorophyll question?....the first one where it says *how can you show that this green solution contains chlorophyll*?...and the second one that has 3 marks!...*expain the role of chlorophyll*?...
u add iodine it turns black, i wrote stuff like photosynthesis, and gives it its colour, and absorbs light etc, last time i read bout chlorophyll was years ago lol
the answer was put one drop of chlorophyll beside one drop of pigment on the blotting paper.
-
YES I PUT T3PO4 as well!!! ;D :D ;) :)
-
I am so curious to find out the answers so pls answer my following questions:
1 What was the formulae of the metal T?n how to do that
2 What will be (needed to produce/produced by the hydrolysis) of the ester
(where the 2 blanks were given)
3 What was the test to show that both lactic acid and acrylic acid contained the COOH group
I hope i'll get the answers soon
Thanx.
i wrote t3po4
hydrolysis of an ester the corresponding alcohol n acid is formed
test i wrote red litmus turns blue
i wrote T3(po4)2 because the wen the volume was 2 the height was 4 so the height was double the volume so 2
-
YES I PUT T3PO4 as well!!! ;D :D ;) :)
don't wanna make u worried but i wrote T3(po4)2
because the hieht was double the volume
sum1 tell me did i do it right or wrong? ???
-
I am so curious to find out the answers so pls answer my following questions:
1 What was the formulae of the metal T?n how to do that
2 What will be (needed to produce/produced by the hydrolysis) of the ester
(where the 2 blanks were given)
3 What was the test to show that both lactic acid and acrylic acid contained the COOH group
I hope i'll get the answers soon
Thanx.
i wrote t3po4
hydrolysis of an ester the corresponding alcohol n acid is formed
test i wrote red litmus turns blue
i wrote T3(po4)2 because the wen the volume was 2 the height was 4 so the height was double the volume so 2
kim v r rite. i also wrote T3(po4)2
-
In the 2 blank questions i wrote first hydroxyl then carboxyl, then i noticed 'an' which means it must start with a vowel. I ignored that then continued then in the last part of the question they ask u how could u show that both contained acid group,so i thought about that and changed my answers to acid and alkanol......wat do u think??????:S:S:S:S
-
What's alkanol?
-
ya wats alkanol?
-
alkanols are all alcohols, or anything with an OH functional group. Alkyls are NOT functional groups, so alkyls cannot be correct.
-
i wrote alkenes and alcohols
im sure deyr both functional groups bt i dnt know if im ryt about alkenes
hopefully atleast 1 mark for alcohols
-
youre write...
and i got t3po4.
not t3po42
i used the n = c x V
and since c was constant, n is proportional to v
something like that.
i got t3po4
I also got : T3PO4....YAY!!!
It's because the ratio required to form the insoluable salt was 3:1 :) :)
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YES I PUT T3PO4 as well!!! ;D :D ;) :)
don't wanna make u worried but i wrote T3(po4)2
because the hieht was double the volume
sum1 tell me did i do it right or wrong? ???
i also wrote da same...... don't worry v r rite... lol :o
-
Hey guys for the empircal formula Question
u dividde the percentage by the RMM right i got 1.5 for mg i dont remember for the other element but if u get 1.5 is it times both by 2?
-
oh
i got Mg3N2
by da way, which was in excess?
and wa was the no. of moles??????
-
What makes you so sure ?!?
By the way I wrote that too but many are saying it's T3PO4
-
I am so curious to find out the answers so pls answer my following questions:
1 What was the formulae of the metal T?n how to do that
2 What will be (needed to produce/produced by the hydrolysis) of the ester
(where the 2 blanks were given)
3 What was the test to show that both lactic acid and acrylic acid contained the COOH group
I hope i'll get the answers soon
Thanx.
1. T3(PO4)2
2. i wrote Alkyl n alcohol
3. litmus ppr. turns BLUE litmus RED
litmus is an indicator ;)
-
Fluorine was in excess and silicon was the limitin reagent....
0.08 was the no of moles....cz the product is the same as dat of the limitin agent...dats wat i read in the txt bk...
-
What makes you so sure ?!?
By the way I wrote that too but many are saying it's T3PO4
believe me none of us are sure of our answers and dont worry I m sure we all will get marks that question was like wat 3 martks?so i m sure they will giv us 2 for nearly gettin our answers!!!!!!!!!!!!!!!!!!!!!!!!hehehe
-
wa did u rite 4 da properties of Cao
i rote 1) it is basic
2)it is soluble in water
and 4 the excess que. i got flourine
do u think mi answers r rite??????????????????
-
1-WASHING THE PRECIPtate to remove impurities and get pure salt
2-heating in an oven to evaporate water and drying the salt
3-t3po4, because 18.0cm3 of T completely reacted with 6.0cm3 of po4 (from graph) there fore 18 is three times 6 .................
4-last page
i-the emperical formulae was Mg3N2
ii-silicon was limiting reagent
iii-0.08 moles
This is what i wrote exactly :) hope its correct
-
was da qus bout the one in excess or da limiting reagent????????????
-
"Fluorine was in excess and silicon was the limitin reagent....
0.08 was the no of moles....cz the product is the same as dat of the limitin agent...dats wat i read in the txt bk..."
Yup!..i wrote silicon was the limiting reagent...........and for the very last question...i wrote 0.09 moles...!....hope its right...
I totally screwed up my exam!!....i think i'm going down to a C/D now...
-
1-WASHING THE PRECIPtate to remove impurities and get pure salt
2-heating in an oven to evaporate water and drying the salt
3-t3po4, because 18.0cm3 of T completely reacted with 6.0cm3 of po4 (from graph) there fore 18 is three times 6 .................
4-last page
i-the emperical formulae was Mg3N2
ii-silicon was limiting reagent
iii-0.08 moles
This is what i wrote exactly :) hope its correct
my moles was soo wrong
i got 0.095
cause i divided the value of f2 by 2
anyways themg2n3 taht is wrong cause u see after u get that u have to divide the values by the smallest which means 3/2=1.5=2 and 2/2=1 so the formuls mg2n(2 because u take the whole number)
-
the ques was about the limiting reagent....
n 0.09 moles is nt rite....its 0.08 moles...
i messed up in the T metal thing...maybe also abt chloropyll....i rote the answer but not sure abt it....
-
oops, i only rote dat flourine was in excess >:( any problem???
wa did u ppl rite in da 2 blanks?????
i rote carboxyl & hydroxyl
do u think it s rite? ??? :( :-\
-
the two blanks abt the acrylic acid??
well the answer was lactic acid and water
-
i messed up in the moles the last part only luckily but u never know how much more i have messed up
and in the blanks i wrote acid and alcohol group
-
i think so u guys got sum other variant...
-
atuallt i dont realli remember the ppr...the ques i mean..
-
oh, no zara i was askin bout wich groups?
so kim is it rong 2 say carboxyl & hydroxyl??
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oh, no zara i was askin bout wich groups?
so kim is it rong 2 say carboxyl & hydroxyl??
]
nopt that i know of cause it means the same thing cause u just wrote more bigger terms
sp dont worry u got ur 2 marks or 1 mark or watver it was
-
the two blanks abt the acrylic acid??
well the answer was lactic acid and water
urgh thank god umm not the onli one who rote that.. <3..
By the way what did u guys ryte for the question abt making sure its an acid.. ??
-
for the bond energies they were H----H and F----F and 2H----F
we add the bond energies for H----H and F----F
then we multiply 2 by H----F
then we subtract (H----H + F----F)- (2*H---F)
the ans will be negative
wohoo i did the same thng.. got a -530 :S.. or sumthn..
-
the two blanks abt the acrylic acid??
well the answer was lactic acid and water
urgh thank god umm not the onli one who rote that.. <3..
By the way what did u guys ryte for the question abt making sure its an acid.. ??
i rote react it with a base.....salt and water will form....though im nt sure if its rite or rong...
-
i rote sumthin like add a magneisum (or any metal) ribbon and if its acidic it'll react.. ??? ??? ::) dont kno tho..
-
i rote silicon was the limitin reagent but ppl keep sayin it was fluorin..
i rote silicon cus it was in shotest supply :S..
-
yeah loco.. I rote silion too... itt had the least amount of moles...
-
what was the answer for chorophyll?
-do chromatography for the cholorophyll sample and compare the results with the one drawn above it will give one spot matching with the same height in both.
-
i rote sumthin like add a magneisum (or any metal) ribbon and if its acidic it'll react.. ??? ??? ::) dont kno tho..
But GUYS.... the question asked how you could determine the compounds contained the same COOH group!! Just because it reacts with a base or a carbonate wont tell that its a COOH group.
-
u guys, i drew a chormatography diagram for the first, its okay rite?
for the energy thing i got -530
for the adv of PLA i rote, its non biodegradable and wont pollute the environment wen burnt with harmful gases (CO2) :S
the source for nitrogen, i said nitrogen fixation bacteria :(
i said we wash the precipitate to remove impurities
and put it in the oven to get it in molten state if needed
cn anyone pls verify my answers..?
the question after the limiting agent one, was how much of mass of SiF was collected rite? i forgot
by the look of it, i think i lost 10-15 marks :(
does anyone, by any chance noe if that cn still be an A/A*
i thoght the paper was too long, we usually get 7 questions. and it was a whole lotta math/bio, weird.
-
heY everYone,
wat about electrolysis of dilute sodium chloride???
Cathode..........
anode..............
and wat happens to the electrolyte???.....
WaiTinG 4 uR RepLies!!xD!! :o
-
at the cathode hydrogen is produced, at the anode oxygen is produced and the electrlyte becomes more concentrated.
-
heY everYone,
wat about electrolysis of dilute sodium chloride???
Cathode..........
anode..............
and wat happens to the electrolyte???.....
WaiTinG 4 uR RepLies!!xD!! :o
Dont take my answer for granted..but I wrote..
Cathode: Hydrogen
Anode: Chlorine
And what happens? umm I think i wrote that Sodium Hydroxide was formed.
Dunno, makes sense tho, tell me what u think
-
I dNtThinK so......becoZ iF iTs DiLTuTe then uve Got Hydrogen on the cathode.........and oxygen on the anode becoz its not concentrated!!!!So the ELEcTroLyte wiLL remAin sodium chloride!!! ::)
Check out htis website,,,its got all the explanation oR go youtube nd watch the video!!!
http://chem.lapeer.org/Chem2Docs/chlorine.html
-
hey does anybody know what were the raw materials of nitrogen & hydrogen????
-
Do you mean the matrial used to make nitrogen and hydrogen?
could be nitrogen from the air and either hydrocarbons or water to make hydrogen. Hydrogen and nitrogen are the raw material used to make ammonia.
-
Nitrogen from air
Hydrogen from Methane and Water reaction
-
hydrogen:alkanes like butanol
nitrogen:air
anybody wants ans or explainations to answer for the chem exam i can help u guys...
and By the way about the phosphate thingy, u must go with tht hight of precipitate graph, cuz writing the reason which goes like this "it mus be a reactive metal so it could displace sodium, and must be soluble" then i feel its wrong , cuz u didnt go with the question...(this ques is the only ques i mess up in)
-
for nitrogen I said air but for hydrogen I said crude oil since the question said the "raw materials".
-
By the way . condesation HAS NO DOUBLE BONDS.
the ans is condesation, cuz it simple molecules like water was removed, and it was not such a sunstance tht contain double bonds (ie. alkenes)
hmm... 1)does crude oil come with alkane or 2)u get alkanes from crude oil, i dont know , but if its 1 then im sure ur correct etch
-
hiiiiiiiiii every1
shogun can u tell me the formula u got 4 da phosphate?
all da best 4 da rest of ur xams
-
heY everYone,
wat about electrolysis of dilute sodium chloride???
Cathode..........
anode..............
and wat happens to the electrolyte???.....
WaiTinG 4 uR RepLies!!xD!!
-
heY everYone,
wat about electrolysis of dilute sodium chloride???
Cathode..........
anode..............
and wat happens to the electrolyte???.....
WaiTinG 4 uR RepLies!!xD!! :o
Dont take my answer for granted..but I wrote..
Cathode: Hydrogen
Anode: Chlorine
And what happens? umm I think i wrote that Sodium Hydroxide was formed.
Dunno, makes sense tho, tell me what u think
The electrolyte is used up nothing is formed
-
hiiiiiiiiii every1
shogun can u tell me the formula u got 4 da phosphate?
all da best 4 da rest of ur xams
Its K2PO4 :)
-
heY everYone,
wat about electrolysis of dilute sodium chloride???
Cathode..........
anode..............
and wat happens to the electrolyte???.....
WaiTinG 4 uR RepLies!!xD!!
Cathode:sodium
anode chloride
electrolyte: used up
+rep me
-
i wrote alkenes and alcohols
im sure deyr both functional groups bt i dnt know if im ryt about alkenes
hopefully atleast 1 mark for alcohols
it was carboxylic acids n alcohols
-
hiiiiiiiiii every1
shogun can u tell me the formula u got 4 da phosphate?
all da best 4 da rest of ur xams
Its K2PO4 :)
lol i got P3PO4 it cant be p2 cuz the valency of p4 is 3
-
heY everYone,
wat about electrolysis of dilute sodium chloride???
Cathode..........
anode..............
and wat happens to the electrolyte???.....
WaiTinG 4 uR RepLies!!xD!!
at da cathode it was h2
at anode it was o2
so conc. NaCl was left
-
By the way to make an ester, u must write
carboxylic/ carboxylic gourp / or at least COOH AND hydroxyl/hydorxyl group/alcohols or atleast Oh
^and waht notty_me said about the elctrolysis stuff is correct..
-
i got this tooooooo
but how do we no wats da valency of T?????????/
-
heY everYone,
wat about electrolysis of dilute sodium chloride???
Cathode..........
anode..............
and wat happens to the electrolyte???.....
WaiTinG 4 uR RepLies!!xD!!
Cathode:sodium
anode chloride
electrolyte: used up
+rep me
nonono-the dilute sodium chloride means that you have more H+ and OH- in solution than Na+ and Cl-
soo
at the cathode, reduction occurs-in this DILUTE solution, hydrogen gas forms (half equation: 4H+(aq) + 4e-->2H2(g)
at the anode, OH- ions give up electrons, since not many Cl- ions are present. Oxygen bubbles off: 4OH- -->O2(g) +2H2O(l) +4e
When the hydrogen and oxygen bubble off, the Na+ and Cl- ions are left behind-so we still have a solution of sodium chloride!
The overall result is that water has been decomposed.
And for the Haber process question:
Air is nearly 80% nitrogen and 20% oxygen, with just small amounts of other gases. The oxygen is removed by burning hydrogen in the air.
2H2(g) + O2(g) -->2H2O (l)
That leaves mainly nitrogen.
Or you can say "the fractional distillation of liquid air"-another way to obtain nitrogen.
For Hydrogen:It is usually made from natural gas or methane, and water (as steam):
CH4(g) + 2H2O (g) -->(catalyst) CO2 (g) +4H2(g)
or you can crack compounds in oil (the alkanes)
-
see on the anode is oxygen on the (u cannot expect water to be stucked at the anode u know)
then hydrogen on the cathode as it is dilute and aqueous leveng chlorine and sodium, giving sodium chloride.
-
By the way to make an ester, u must write
carboxylic/ carboxylic gourp / or at least COOH AND hydroxyl/hydorxyl group/alcohols or atleast Oh
isnt it dicarboxylic or diol?????
-
i got this tooooooo
but how do we no wats da valency of T?????????/
plzzzzzzzzzz i need a reply
thanx
-
i wrote t3(po4)2
meaning my T valency was 2 because in the graph the height of the precipitate was twice the height of the volume so i wrote 2 many in my skul did dat
-
thts for u to guess, we dont know.
this is what the question ask, the question in short says what is the valency of metal T, and u will only get the formula if u know the valency of T, but to get it, its for u to find out...
i got mine as 1 others got 2...
-
i wrote t3(po4)2
meaning my T valency was 2 because in the graph the height of the precipitate was twice the height of the volume so i wrote 2 many in my skul did dat
yeeees-I got the same as you!: )
-
i got 1 since they gave us conc. and volume so i calculated no. of moles and wrote a balanced ionic equation it was somethin like this 18T+6P04=6T3p04
-
what about the chlorophyll question?....the first one where it says *how can you show that this green solution contains chlorophyll*?...and the second one that has 3 marks!...*expain the role of chlorophyll*?...
1) i think u should put the pure sample of chlorophyll in the pencil line a long with a sample from the green solution ,, the pure sample cuz its pure is gonna give one spot on the paper, but the green solution is gonna give many so if there a spot that matches the spot of the pure sample that means that it actually contains chlorophyll.
2) chlorophyll traps sunlight need for the process
it also acts as the catalyst for the reaction
it also gives the plant its green color
-
hiiiiiiiiii every1
shogun can u tell me the formula u got 4 da phosphate?
all da best 4 da rest of ur xams
Its K2PO4 :)
lol i got P3PO4 it cant be p2 cuz the valency of p4 is 3
I've discussed the question with my teacher and she said that its K2PO4 ....potassium displaces sodium from it salt because potassium is more reactive than sodium. :D
-
even i thought its potassium.. but isnt the valency of the radicle phosphate is 3....
-
hiiiiiiiiii every1
shogun can u tell me the formula u got 4 da phosphate?
all da best 4 da rest of ur xams
Its K2PO4 :)
lol i got P3PO4 it cant be p2 cuz the valency of p4 is 3
I've discussed the question with my teacher and she said that its K2PO4 ....potassium displaces sodium from it salt because potassium is more reactive than sodium. :D
It can't be K2PO4
PO4 is 3-
K is +1
phosphates form with ferrous metals, the most likely candidates being iron or nickel
it was a 2+ metal as the precipitate height was twice that of the volume used (although thinking back now did the concentration work out to 1 mole??? urgh)
^^
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what i think was that the value of the height had nothing to do with the volume, since height was in mm, and volume in cm3. I just remember that, 18 cm3 of aqueous nitrate of T, reacted with 2 cm3 portions of a solution of Na3PO4. The maximum precipitate of the phosphate of T, was reached at 6 cm3 of sodium phosphate. Since both had the same concentration, it didnt really matter, the main thing that mattered was the volume then. Now, we have that the volume of the nitrate of T used was 18, and that of the sodium phosphate was 6. so volume ratio of the nitrate reactant to the phosphate reactant is 18:6 = 3:1, which is also the mole ratio. So if we construct an ionic equation using the mole ratio, we can get ...
PO43- + 3T+ ----> T3PO4
when i came home, i opened june 2004 paper 3, of chem, where i remember seeing a similar graph as the one given in the question..
in the june 2004 q, 4 cm3 of aqueous iron (III) chloride, reacts with 2cm^3 portions of aqueous sodium hydroxide..according to the graph..the maximum volume of sodium hydroxide at which the maximum precipitate is formed, is at 12 cm^3..
thus the volume ratio of the chloride reactant to the hydroxide, is 4:12 = 1:3
That means, there will be one Fe3+ ion for every 3 OH- ions..according to the ratio..
the next part of the given is..complete the following reaction..
Fe3+ + .....OH- -----> ...........
since ratio is 1:3..itll be 3 OH- forms Fe(OH)2..
the concentration of both reactants is 1moldm-3 which is given..
so the questions are quite similar..and so, i think T3PO4
i dont consider myself a genius, just mixxing familiar stuff with unfamiliar stuff.
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sorry...that is Fe(OH)3
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it wasnt OH in tht fe thing it was some halogen i think, im100% sure it wasnt OH in the fill in the blanks stuff for tht ionic reaction. however ure explaination is good.
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i just rechecked it..and it is aqueous sodium hydroxide, and aqueous iron (III) chloride..as the reactants..:S
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At da cathod(da negativ electrod) u gt H2+ ions atraced n dey giv H2 gas at cathod. At da anode wich is positiv, da negtiv ions dat r Cl- ions r atracted n dey giv off Cl2 gas. A solution of NaOH is left behind ;D
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heY everYone,
wat about electrolysis of dilute sodium chloride???
Cathode..........
anode..............
and wat happens to the electrolyte???.....
WaiTinG 4 uR RepLies!!xD!!
at da cathode it was h2
at anode it was o2
so conc. NaCl was left
NOPE its was concentrated NaCl
therefore @ anode Cl would be depsoed no O2
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no... im pretty sure it said dilute sodium chloride
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properties of Cao
did it come....cause i think there is diffrent papers
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Guyz...
a bad news
test 4 carboxylic acis is not litmus ppr
the question was to give a test to show that it contains -COOH ions
i searched the net
googled "test 4 carboxylic acid Chemistry" n got the ans.
Test: add water then add sodium hydrogen carbonate
Result: Fizzing and a white ppt. at the bottom
This test is specifically for carboxylic acids and i think they asked this one
not the little litmus paper....... :( :( :(
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properties of CaO came in the way, that the ionic structure we had to draw was originally calcium oxide, so we had to tell its properties..
and, about organic acids..i think syllabus specifies that we have to know about ehtanoic acid as a typical weak acid..and so..TYPICAL weak ACID, means, that it reacts in the same way with litmus, metal carbonates, hydroxides, oxides, and even metal themselves as mineral acids..well..when we have to test for an acid, we guys used to use the carbonate test, effervescence occurs, and the gas produced turns limewater milky...what about the rest of you??
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I just can't understand why the CIE nutshells wrote "to show the -COOH"
y not just "to show that they r week acids"
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lol..maybe thts a way to make sure the candidate even knows that -COOH is for a carboxylic acid..
well..what did you write for this acid test?
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For the COOH thingy, i wrote add and alcohol and an ester should form :-\ Its a long shot i know, but at least its a test to show that they have the COOH group and not just to show that they are acids.
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which question was "to show a test to distinguish b/w the two?"
one had a double bond so i did add Bromine, and it would decoulirise unlike the other, forgot which question it was.
and guys, how much is the boundary for an A? does anyone noe?
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which question was "to show a test to distinguish b/w the two?"
one had a double bond so i did add Bromine, and it would decoulirise unlike the other, forgot which question it was.
and guys, how much is the boundary for an A? does anyone noe?
I wrote the same thing. Shake with bromine water.
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it wasnt OH in tht fe thing it was some halogen i think, im100% sure it wasnt OH in the fill in the blanks stuff for tht ionic reaction. however ure explaination is good.
Trust me man K2PO4 is right otherwise my teacher and a couple of A* students are wrong :) it was a tough question though xD
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heY everYone,
wat about electrolysis of dilute sodium chloride???
Cathode..........
anode..............
and wat happens to the electrolyte???.....
WaiTinG 4 uR RepLies!!xD!!
at da cathode it was h2
at anode it was o2
so conc. NaCl was left
NOPE its was concentrated NaCl
therefore @ anode Cl would be depsoed no O2
um totally sure it was DILUTE aqueos sodium chloride because i saw the test after we did it by 1 day(24 hours!!) from our teacher in sKewL!!!xD!! ;D
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heY everYone,
wat about electrolysis of dilute sodium chloride???
Cathode..........
anode..............
and wat happens to the electrolyte???.....
WaiTinG 4 uR RepLies!!xD!!
at da cathode it was h2
at anode it was o2
so conc. NaCl was left
NOPE its was concentrated NaCl
therefore @ anode Cl would be depsoed no O2
um totally sure it was DILUTE aqueos sodium chloride because i saw the test after we did it by 1 day(24 hours!!) from our teacher in sKewL!!!xD!! ;D
yup it was dilute..
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Guys there are a few questions i wanted to make sure that they are correct
1-heat the solution--> i wrote to seperate crystals from water
2-what type of organic compound has the following linkage--->polyester
3-the complete question an alchohol group and an acid group (didnt write organic before acid:/)
4-advantages -->biodegradable so it wont cause pollution
5-water behaves as a base-->cuz its a proton acceptor
6- for the equation between sodium flouride and calcium chloride why was double the volume of NaF added?-->i wrote cuz 1 mole of CaCl2 reacts with 2 moles of NaF
7-condensation or addition? condensation cuz water was removed from the monomer
8-the stronger acid was HCl cuz it was 97% ionized
9-ph of HCl will be lower than the other acid (Or do i have to write values)?
10-for the raw materials i wrote -->fractional distillation of liquified air and cracking of an alkane (didnt notice that the process wasnt required)
11-the moles 0.07 same as silicon?and could somebody plz explain which one is limiting and why?
12-for the T formula i got the formula wrong but i wrote the volume of phosphate solution is double the volume of metal T nitrate solution for the explanation
13-for the exothermic reaction i got the values of reactants and products and checked which has greater value
I know the q's are too many but im kinda freaked out cuz i did very badly in the exam
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what i think was that the value of the height had nothing to do with the volume, since height was in mm, and volume in cm3. I just remember that, 18 cm3 of aqueous nitrate of T, reacted with 2 cm3 portions of a solution of Na3PO4. The maximum precipitate of the phosphate of T, was reached at 6 cm3 of sodium phosphate. Since both had the same concentration, it didnt really matter, the main thing that mattered was the volume then. Now, we have that the volume of the nitrate of T used was 18, and that of the sodium phosphate was 6. so volume ratio of the nitrate reactant to the phosphate reactant is 18:6 = 3:1, which is also the mole ratio. So if we construct an ionic equation using the mole ratio, we can get ...
PO43- + 3T+ ----> T3PO4
when i came home, i opened june 2004 paper 3, of chem, where i remember seeing a similar graph as the one given in the question..
in the june 2004 q, 4 cm3 of aqueous iron (III) chloride, reacts with 2cm^3 portions of aqueous sodium hydroxide..according to the graph..the maximum volume of sodium hydroxide at which the maximum precipitate is formed, is at 12 cm^3..
thus the volume ratio of the chloride reactant to the hydroxide, is 4:12 = 1:3
That means, there will be one Fe3+ ion for every 3 OH- ions..according to the ratio..
the next part of the given is..complete the following reaction..
Fe3+ + .....OH- -----> ...........
since ratio is 1:3..itll be 3 OH- forms Fe(OH)2..
the concentration of both reactants is 1moldm-3 which is given..
so the questions are quite similar..and so, i think T3PO4
i dont consider myself a genius, just mixxing familiar stuff with unfamiliar stuff.
Dude I love You!!
I used exact same reasoning!!!!!
Atleast now i know i used valid reasoning!!
Thank you!
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Guys there are a few questions i wanted to make sure that they are correct
1-heat the solution--> i wrote to seperate crystals from water
2-what type of organic compound has the following linkage--->polyester
3-the complete question an alchohol group and an acid group (didnt write organic before acid:/)
4-advantages -->biodegradable so it wont cause pollution
5-water behaves as a base-->cuz its a proton acceptor
6- for the equation between sodium flouride and calcium chloride why was double the volume of NaF added?-->i wrote cuz 1 mole of CaCl2 reacts with 2 moles of NaF
7-condensation or addition? condensation cuz water was removed from the monomer
8-the stronger acid was HCl cuz it was 97% ionized
9-ph of HCl will be lower than the other acid (Or do i have to write values)?
10-for the raw materials i wrote -->fractional distillation of liquified air and cracking of an alkane (didnt notice that the process wasnt required)
11-the moles 0.07 same as silicon?and could somebody plz explain which one is limiting and why?
12-for the T formula i got the formula wrong but i wrote the volume of phosphate solution is double the volume of metal T nitrate solution for the explanation
13-for the exothermic reaction i got the values of reactants and products and checked which has greater value
I know the q's are too many but im kinda freaked out cuz i did very badly in the exam
1.to remove all the water
2.polyester
3.dont remember the ques
4.correct but they asked for two so u had to rite one more.
5.correct
6.dont remember if it came.
7.correct
8.dont remember the ques well..
9.even this one>>dont remember..
10.liquid air and methane
11.0.08>>same as silicon
12.i got this rong
13.dont remember the ques..
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yay so the polyester one is right!!...but for silicon how come is it 0.08 i remember the ques was 0.07 moles of silicon reacted with 25 g of bromine O.o??maybe there were some differences in the exam...any more feedback?
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well...different variant...well if silicon in ur ppr was 0.07 den the product will also be the same as dat of the limiting reagent.....n if in ur ppr it was COO...the linkage i mean well den its polytester...
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yeah cuz some ppl kept sayin its ester or fats it didnt make any sense to me....anyone else? feedback?
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what i think was that the value of the height had nothing to do with the volume, since height was in mm, and volume in cm3. I just remember that, 18 cm3 of aqueous nitrate of T, reacted with 2 cm3 portions of a solution of Na3PO4. The maximum precipitate of the phosphate of T, was reached at 6 cm3 of sodium phosphate. Since both had the same concentration, it didnt really matter, the main thing that mattered was the volume then. Now, we have that the volume of the nitrate of T used was 18, and that of the sodium phosphate was 6. so volume ratio of the nitrate reactant to the phosphate reactant is 18:6 = 3:1, which is also the mole ratio. So if we construct an ionic equation using the mole ratio, we can get ...
PO43- + 3T+ ----> T3PO4
when i came home, i opened june 2004 paper 3, of chem, where i remember seeing a similar graph as the one given in the question..
in the june 2004 q, 4 cm3 of aqueous iron (III) chloride, reacts with 2cm^3 portions of aqueous sodium hydroxide..according to the graph..the maximum volume of sodium hydroxide at which the maximum precipitate is formed, is at 12 cm^3..
thus the volume ratio of the chloride reactant to the hydroxide, is 4:12 = 1:3
That means, there will be one Fe3+ ion for every 3 OH- ions..according to the ratio..
the next part of the given is..complete the following reaction..
Fe3+ + .....OH- -----> ...........
since ratio is 1:3..itll be 3 OH- forms Fe(OH)2..
the concentration of both reactants is 1moldm-3 which is given..
so the questions are quite similar..and so, i think T3PO4
i dont consider myself a genius, just mixxing familiar stuff with unfamiliar stuff.
Dude I love You!!
I used exact same reasoning!!!!!
Atleast now i know i used valid reasoning!!
Thank you!
well..in my paper..i just wrote the formula, the first thing in my answer..then i made it clear the two volumes of the solution, then somehow i got a balanced symbol equation and wrote it down, and wrote after it..tht above is the chemical equation, according to the volume and mole ratios..hope thts an explanation that'll suffice
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1.right
2.i think it's fats
3.i wrote alcohol and carboxylic acid
4. right
5.right
6. in variant 2 the q was diff. but your answer is right
7.right
8. right
9. i think you had to write values as well
10.umm..maybe its right, but i think a mark will be deducted for not writing raw materials because that was the next part
11. right. silicon was the limiting reagent because it had less moles than fluorine in the ratio 1:1
12. t3po4 i think, but maybe its diff. in other variants
13. right
all of my friends were saying theirs were bad too, so i think the a threshhold will be low (i hope so anyway because it was wayy too difficult and long). I hope it helps. But i'm glad the table from the study guide came, i was memorising it like crazy half an hour before ;D
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Guys there are a few questions i wanted to make sure that they are correct
1-heat the solution--> i wrote to seperate crystals from water
2-what type of organic compound has the following linkage--->polyester
3-the complete question an alchohol group and an acid group (didnt write organic before acid:/)
4-advantages -->biodegradable so it wont cause pollution
5-water behaves as a base-->cuz its a proton acceptor
6- for the equation between sodium flouride and calcium chloride why was double the volume of NaF added?-->i wrote cuz 1 mole of CaCl2 reacts with 2 moles of NaF
7-condensation or addition? condensation cuz water was removed from the monomer
8-the stronger acid was HCl cuz it was 97% ionized
9-ph of HCl will be lower than the other acid (Or do i have to write values)?
10-for the raw materials i wrote -->fractional distillation of liquified air and cracking of an alkane (didnt notice that the process wasnt required)
11-the moles 0.07 same as silicon?and could somebody plz explain which one is limiting and why?
12-for the T formula i got the formula wrong but i wrote the volume of phosphate solution is double the volume of metal T nitrate solution for the explanation
13-for the exothermic reaction i got the values of reactants and products and checked which has greater value
I know the q's are too many but im kinda freaked out cuz i did very badly in the exam
1 - to dry it - remove water from the precipitate
2 - well..i wrote esters, cuz they mainly asked, which type of compound got the OCO linkage, so, i think answer can be esters/fats/polyesters
3 - i think the q asked, what functional groups did the monomer have, so that, it forms an OCO linkage (ester linkage)..so i wrote..it had the -OH and the -COOH group..because, H from -OH is taken, and OH from -COOH is taken, to form water, leaving behind OCO..
4 - for this, i wrote..since its biodegredable, it wont fill up landsites, and so, more space available as landfill sites, and second, i wrote, it won't cause visual pollution (unpleasant to look at) the way normal plastics are.
5 - yup, proton acceptor
6 - my question was why was thrice the volume of something fluoride, needed to react with iron (III) something....?!?!
7 - condensation, water, yup
8 - yea, HCl strong acid, the other one weak
9 - values werent necessary, as long as you clearly wrote that, the stronger acid had a lower pH than the other one
10 - i wrote..liquid air for nitrogen, and for hydrogen, methane and steam
11 - i had 0.08 for silicon, so thts wht i wrote in the last q..and about limiting, now i dont know what mass of fluorine was given to you (some of my friends were saying that this question didnt have fluorine, but it had CHLORINE, anyone had such a question?!)
12 - i wrote my answer before.
13 - what i did was (energy used to break bonds - energy released when forming bonds), got something like -530, which means exothermic
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Guys there are a few questions i wanted to make sure that they are correct
1-heat the solution--> i wrote to seperate crystals from water
2-what type of organic compound has the following linkage--->polyester
3-the complete question an alchohol group and an acid group (didnt write organic before acid:/)
4-advantages -->biodegradable so it wont cause pollution
5-water behaves as a base-->cuz its a proton acceptor
6- for the equation between sodium flouride and calcium chloride why was double the volume of NaF added?-->i wrote cuz 1 mole of CaCl2 reacts with 2 moles of NaF
7-condensation or addition? condensation cuz water was removed from the monomer
8-the stronger acid was HCl cuz it was 97% ionized
9-ph of HCl will be lower than the other acid (Or do i have to write values)?
10-for the raw materials i wrote -->fractional distillation of liquified air and cracking of an alkane (didnt notice that the process wasnt required)
11-the moles 0.07 same as silicon?and could somebody plz explain which one is limiting and why?
12-for the T formula i got the formula wrong but i wrote the volume of phosphate solution is double the volume of metal T nitrate solution for the explanation
13-for the exothermic reaction i got the values of reactants and products and checked which has greater value
I know the q's are too many but im kinda freaked out cuz i did very badly in the exam
1 - to dry it - remove water from the precipitate
2 - well..i wrote esters, cuz they mainly asked, which type of compound got the OCO linkage, so, i think answer can be esters/fats/polyesters
3 - i think the q asked, what functional groups did the monomer have, so that, it forms an OCO linkage (ester linkage)..so i wrote..it had the -OH and the -COOH group..because, H from -OH is taken, and OH from -COOH is taken, to form water, leaving behind OCO..
4 - for this, i wrote..since its biodegredable, it wont fill up landsites, and so, more space available as landfill sites, and second, i wrote, it won't cause visual pollution (unpleasant to look at) the way normal plastics are.
5 - yup, proton acceptor
6 - my question was why was thrice the volume of something fluoride, needed to react with iron (III) something....?!?!
7 - condensation, water, yup
8 - yea, HCl strong acid, the other one weak
9 - values werent necessary, as long as you clearly wrote that, the stronger acid had a lower pH than the other one
10 - i wrote..liquid air for nitrogen, and for hydrogen, methane and steam
11 - i had 0.08 for silicon, so thts wht i wrote in the last q..and about limiting, now i dont know what mass of fluorine was given to you (some of my friends were saying that this question didnt have fluorine, but it had CHLORINE, anyone had such a question?!)
12 - i wrote my answer before.
13 - what i did was (energy used to break bonds - energy released when forming bonds), got something like -530, which means exothermic
for number 11 we had bromine lol...so the limting reagent will have more number of moles?
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I can clearly remember that for the volume of sodium phosphate and the tnitrate it was '2cm3 and 18 cm3'...
And that what mixed me up! May be some variant papers?!
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bromine? How many different variants were there? :P
well..it depends on the mole ratio..
for example, in my paper, it was 0.08 moles of silicon reacts with 7.2g of fluorine, the equation given was
Si + 2F2 ----> SiF4
so, silicon and fluorine are in the mole ratio 1:2
the moles of fluorine given is 7.2/(19x2) = 7.2/38 = 0.189 moles....(we use 38, cuz its diatomic, so we take double the original Ar
so that means, if fluorine is 0.189 moles, then according to the mole ratio, silicon should be 0.189/2 = 0.095 moles...but it is 0.08..meaning, silicon is limiting..
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bromine? How many different variants were there? :P
well..it depends on the mole ratio..
for example, in my paper, it was 0.08 moles of silicon reacts with 7.2g of fluorine, the equation given was
Si + 2F2 ----> SiF4
so, silicon and fluorine are in the mole ratio 1:2
the moles of fluorine given is 7.2/(19x2) = 7.2/38 = 0.189 moles....(we use 38, cuz its diatomic, so we take double the original Ar
so that means, if fluorine is 0.189 moles, then according to the mole ratio, silicon should be 0.189/2 = 0.095 moles...but it is 0.08..meaning, silicon is limiting..
I took the mole ratio(1:2)
so if silicon was 0.08 then fluorine needed was 0.16(0.08x2) which is 0.16x38g(6.08g)
but there was 7.2g, much more than required ans so silicon limiting reagent
different approach but yeah same ans
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yeah loco.. I rote silion too... itt had the least amount of moles...
ROCK ON!!! =] ;D
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ahahaha.. yeah n i found that flourine was in excess.. n i knew ahd to rite the oppsite of what i find in excess.. but nawwsss had to be me n rote flourinee! yayyyy .. sighs ..
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i rote sumthin like add a magneisum (or any metal) ribbon and if its acidic it'll react.. ??? ??? ::) dont kno tho..
But GUYS.... the question asked how you could determine the compounds contained the same COOH group!! Just because it reacts with a base or a carbonate wont tell that its a COOH group.
naa m tlkin abt the one with tells us how do u tell if its an acid.. <3 i gues ther was a different one either that or i totali screwd up :-\
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errr.. hold on a sec.. there was no question as far as i can remember which wanted to know if it COOH group.. what this? .. it asked about how would u determine ts an acid.. hmmm if thts wht ur talkign abt..
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what i think was that the value of the height had nothing to do with the volume, since height was in mm, and volume in cm3. I just remember that, 18 cm3 of aqueous nitrate of T, reacted with 2 cm3 portions of a solution of Na3PO4. The maximum precipitate of the phosphate of T, was reached at 6 cm3 of sodium phosphate. Since both had the same concentration, it didnt really matter, the main thing that mattered was the volume then. Now, we have that the volume of the nitrate of T used was 18, and that of the sodium phosphate was 6. so volume ratio of the nitrate reactant to the phosphate reactant is 18:6 = 3:1, which is also the mole ratio. So if we construct an ionic equation using the mole ratio, we can get ...
PO43- + 3T+ ----> T3PO4
when i came home, i opened june 2004 paper 3, of chem, where i remember seeing a similar graph as the one given in the question..
in the june 2004 q, 4 cm3 of aqueous iron (III) chloride, reacts with 2cm^3 portions of aqueous sodium hydroxide..according to the graph..the maximum volume of sodium hydroxide at which the maximum precipitate is formed, is at 12 cm^3..
thus the volume ratio of the chloride reactant to the hydroxide, is 4:12 = 1:3
That means, there will be one Fe3+ ion for every 3 OH- ions..according to the ratio..
the next part of the given is..complete the following reaction..
Fe3+ + .....OH- -----> ...........
since ratio is 1:3..itll be 3 OH- forms Fe(OH)2..
the concentration of both reactants is 1moldm-3 which is given..
so the questions are quite similar..and so, i think T3PO4
i dont consider myself a genius, just mixxing familiar stuff with unfamiliar stuff.
Dude I love You!!
I used exact same reasoning!!!!!
Atleast now i know i used valid reasoning!!
Thank you!
I Wote the same thing exactly in ma test ,this is SupeRb!!! 8) ;D :P
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u guys for the aq. NaCl question, im scared, i rote H2 at cathode and Cl2 at anode, bt some ppl are saying its O2 at anode. :(
anyone noes da boundary for an A?
the paper was too long :(
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errr.. hold on a sec.. there was no question as far as i can remember which wanted to know if it COOH group.. what this? .. it asked about how would u determine ts an acid.. hmmm if thts wht ur talkign abt..
yea cryps.. thats wht m tlkin abt.. =]
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yea u add any metal carbonates if it fizzes due to liberation of carbondioxide, then its an acid..