IGCSE/GCSE/O & A Level/IB/University Student Forum
Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: vince_24 on November 16, 2009, 05:08:57 am
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So, I happen to be very bad at this. Structured and practical was OK...
Do you guys have any tips? How to study for multi choice?
Any relevant information would be greatly appreciated.
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i would mainly say know your notes well, and if you think you know it well test your knowledge by doing the papers. More practice you get the better you'll do in the exam as most of the time multi-choice questions sometimes repeat...
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i would mainly say know your notes well, and if you think you know it well test your knowledge by doing the papers. More practice you get the better you'll do in the exam as most of the time multi-choice questions sometimes repeat...
Actually in chemistry paper 1 they don't repeat... at most maybe 1-2 questions
But in physics they repeat 3-4 ques....so for chem v really need to stick to knowledge instead of learning by heart!!
By the way which chem paper1 u guys taking? paper 12 or 11? I think its given in ur statement of entry...it should b somthin like: 9701/12 or 9701/11....i'm doin 9701/12
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Yeah, i meant that even though they don't repeat the exact question they usually ask a similar question, so if you understood how to do the question in the past paper you would be able to do the similar question they give you ;). Yeah mainly for Chemistry you need to know your notes and understand the concepts.
9701/12
Good luck with the exams ;D
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9701/12 :(
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I'm going to go through the syllabus again as I feel I have forgotten everything. And what's up with the schedule? I had phy, now bio, then chem. :|
I'll go through some solved paper 1s as well..
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Hey Mani
Do you know where to get Chemistry multi-choice papers for years before 2001?
Thanks.
Good luck with the Chemistry multi-choice.
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Hey Mani
Do you know where to get Chemistry multi-choice papers for years before 2001?
Thanks.
Good luck with the Chemistry multi-choice.
Nah man. :(
I'm gonna go through some MCQs of other boards though. Helps.
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u kno wat??
when we were studyin for bio exam today in d library....we saw stack of exam question papers...it says "9701 chemistry, OCT NOV 2009"....
right before our eyes.......
too bad our "honesty-is-the-best-policy" thingie in our hearts prevented us from peeping the paper......
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u kno wat??
when we were studyin for bio exam today in d library....we saw stack of exam question papers...it says "9701 chemistry, OCT NOV 2009"....
right before our eyes.......
too bad our "honesty-is-the-best-policy" thingie in our hearts prevented us from peeping the paper......
omg!! but don't they open the packet just before the exam starts? :o
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*shrughs* no idea.... it came out of the envelope...and it was several sheets. not only one.
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*shrughs* no idea.... it came out of the envelope...and it was several sheets. not only one.
maybe it was the list of formulas or periodic table.. :-\
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That's pretty careless of your school... cause i could remember when i was in IGCSE, one of the papers went missing and they had to call the police and stuff... apparently they found it inside one of the teachers's car who was transporting the papers :D.
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Well, I scanned this book and it has old paper questions as well.. with the answers, etc.
I hope it helps. Took me hours scanning. It still won't convert to PDF. >:( >:( >:( >:( !@#$
Anywho, it has Introduction to Organic Chemistry, Hydrocarbons and Polymerisation.
It does not include carboxylic acids, carbonyl compounds, and hydrogen derivatives. (I was too tired to scan more, plus I haven't started studying at all..so yeah)
Mainly for Vince, but if others benefit too = :D
Good Luck for the exam guys!
pz
-MaN
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Wow thanks a lot Mani, there are heaps of questions ;D.
+rep. You better get back to studying :P.
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Hard water contains calcium ions and hydrogencarbonate ions arising from dissolved calcium
hydrogencarbonate, Ca(HCO3)2.
How many electrons are present in the hydrogencarbonate anion?
A 30 B 31 C 32 D 33
The answer is C.. can sm1 xplain to me the answer plzz?
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Hard water contains calcium ions and hydrogencarbonate ions arising from dissolved calcium
hydrogencarbonate, Ca(HCO3)2.
How many electrons are present in the hydrogencarbonate anion?
A 30 B 31 C 32 D 33
The answer is C.. can sm1 xplain to me the answer plzz?
1stly,
# Protons = # Electrons
H = 1
C = 6
O = 8x3 = 24
Total = 24+6+1 = 31
HCO3- means it has a negative charge on it. So, it has gained an electron.
Thus, 31+1 = 32 electrons.
:)
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Wow thanks a lot Mani, there are heaps of questions ;D.
+rep. You better get back to studying :P.
You better start* studying. < lol
Thanks.
I'll see if I can scan and upload a few more topics later. :]
I was just frustrated as my Adobe PDF converter was giving errors; for no reason. >:(
gl.
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1stly,
# Protons = # Electrons
H = 1
C = 6
O = 8x3 = 24
Total = 24+6+1 = 31
HCO3- means it has a negative charge on it. So, it has gained an electron.
Thus, 31+1 = 32 electrons.
:)
ah okiie.. thanx dude!!! :-* :)
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ah okiie.. thanx dude!!! :-* :)
Your very welcome. :]
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Well, I scanned this book and it has old paper questions as well.. with the answers, etc.
I hope it helps. Took me hours scanning. It still won't convert to PDF. >:( >:( >:( >:( !@#$
Anywho, it has Introduction to Organic Chemistry, Hydrocarbons and Polymerisation.
It does not include carboxylic acids, carbonyl compounds, and hydrogen derivatives. (I was too tired to scan more, plus I haven't started studying at all..so yeah)
Mainly for Vince, but if others benefit too = :D
+rep, if it helped you.
Good Luck for the exam guys!
pz
-MaNi
OMG...Mani...dude ur da best... THANKU FOR UR EFFORT
Is this a book?? If so then isn't there a ebook for it?? I tried searching for a ebook & got this: http://nowdownloadall.com/your-file.asp?pb=4&PID=92d75e3c-6ff7-408e-8a60-6c1abcebcf98&q=gce%20a%20level%20chemistry%20mcq%20with%20helps (http://nowdownloadall.com/your-file.asp?pb=4&PID=92d75e3c-6ff7-408e-8a60-6c1abcebcf98&q=gce%20a%20level%20chemistry%20mcq%20with%20helps)
But the damn thing asks for payment...i hate these types of download site they advertise everythin is free but in Step 2 suprise suprise!! Any1 know how to get past this & just download that ...helps book??
Any ways...i'm sure atleast 5 questions will come from that helps...book...where is this book from- I don't think CIE is gonna b kind enough to compile such a book! :P
Mani...please do upload the other parts of organics....also if possible the inorganics too! :o
PS: ur scanner software should have scan as pdf or document option...that way it scans into a pdf...thats how mine is like! otherwise go print on the .doc file & select printer as Adobe PDF...that saves the entire .doc as .pdf.... I have Adobe acrobat pro 7; Do u?? Maybe that gives u these features .=P
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It's a singaporian book. No, i couldn't find it online (I searched for days). I got it shipped.
I know how to convert to a PDF, lol. Just an error here and there. So it would halt activity after converting a few pages.
I'll try uploading a few more organic once I have started studying myself. I've been wasting time all day. lol.
You're welcome. :)
Hope it helps.
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Thx forr the attachment MAniiiiiiiiiii... By the way, do you think that P1 is kinda difficult to score A???
I think that we need to read more.. Those are general chemistry that sometimes its not even in the book.. Except for the organic part..
And the frustrating 10 last questions..
Lastly, Any thread discussing Chem P2???
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Yea, the frustating final 10, with more than 1 answer is correct.
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Thx forr the attachment MAniiiiiiiiiii... By the way, do you think that P1 is kinda difficult to score A???
I think that we need to read more.. Those are general chemistry that sometimes its not even in the book.. Except for the organic part..
And the frustrating 10 last questions..
Lastly, Any thread discussing Chem P2???
I think the last 10 are the worst :D
You write an answer, scribble it out, write another, scribble, then finally just do inny minny miny mo. :/ Quite frustrating.
Chem p2, I'm sure there was one. Look in subject doubts. Else, I'll find it when I get on a PC.
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Best of luck guys! Kill it.
:D
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Does anyone know the uses of certain chemical compounds?
They asked something about a bromo-halogenoalkane which was used as a fire extuingisher or something in May/June.
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Heres the PDF Version of what MaNi posted. A lot of chemistry multi choice questions, etc. Very helpful
http://www.megaupload.com/?d=7CBYEBYX
Enjoy.
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Heres the PDF Version of what MaNi posted. A lot of chemistry multi choice questions, etc. Very helpful
http://www.megaupload.com/?d=7CBYEBYX
Enjoy.
Thanks a lot bro. :)
+rep'd.
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Use of the Data Booklet is relevant to this question.
Ethyl ethanoate can be obtained from ethanoic acid and ethanol by the following reaction.
CH3CH2OH + CH3CO2H--> CH3CO2CH2CH3 + H2O
Ethanol (30 g) and ethanoic acid (30 g) are heated under reflux together, and 22 g of ethyl
ethanoate are obtained.
What is the yield of the ester?
A 25 % B 38 % C 50 % D 77 %
the answer is C.. how???
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I think you take out the moles for each then the %yield ..
I can't type the working on my phone; sorry. :(
Use of the Data Booklet is relevant to this question.
Ethyl ethanoate can be obtained from ethanoic acid and ethanol by the following reaction.
CH3CH2OH + CH3CO2H--> CH3CO2CH2CH3 + H2O
Ethanol (30 g) and ethanoic acid (30 g) are heated under reflux together, and 22 g of ethyl
ethanoate are obtained.
What is the yield of the ester?
A 25 % B 38 % C 50 % D 77 %
the answer is C.. how???
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its ok mani... i'll work it ouuuuuut.. Thanks anw... am so sleepy!!! my mind not working!
lol... have a nice day...
n Thanks anyway...
c genti
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its ok mani... i'll work it ouuuuuut.. Thanks anw... am so sleepy!!! my mind not working!
lol... have a nice day...
n Thanks anyway...
c genti
Yes, it's 9 AM at your end.
Get some rest and then attempt papers with a fresh mind.
Good night, err morning.
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Can someone please do November 07 question 16?!
Why cant it be A?
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Can someone please do November 07 question 16?!
Why cant it be A?
hey dude the answer IS A.. LOLSS check the marking scheme well... ::)
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hey dude the answer IS A.. LOLSS check the marking scheme well... ::)
I mean why cant it be C :P sorry.
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I mean why cant it be C :P sorry.
Man put up the question...there will b less confusion!! heres the question:
16 Compound X on refluxing with aqueous sodium hydroxide gave mixture Y which on distillation
with acidified potassium dichromate(VI) produced propanone. Mixing Y with dilute nitric acid and
aqueous silver nitrate gave a cream precipitate.
What could compound X be?
A CH3CHBrCH3
B CH3CHICH3
C CH3CH2CH2Br
D CH3CH2CH2I
Ok so ur right that is could C...since it has Br...which is the only 1 that gives cream ppt
But if u react choice C with NaOH u get a primary alcohol, right???
Then if u react that primary alcohol with dichromate u get a aldehyde & finally carboxylic acid.
But the question says that u get ketone(propanone)...which is the oxidation a secondary alcohol
So if u react choice A with NaOH u get Secondary alcohol as Br replaces OH on that 2nd C atom
Then that secondary alcohol gives ketone on oxidation....
I hope this proves its A.... :P
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Use of the Data Booklet is relevant to this question.
Ethyl ethanoate can be obtained from ethanoic acid and ethanol by the following reaction.
CH3CH2OH + CH3CO2H--> CH3CO2CH2CH3 + H2O
Ethanol (30 g) and ethanoic acid (30 g) are heated under reflux together, and 22 g of ethyl
ethanoate are obtained.
What is the yield of the ester?
A 25 % B 38 % C 50 % D 77 %
the answer is C.. how???
Hmmm... i thought it was B. 38%. It should b C. 50%.... heres why i think:
using mass & Mr of ethanol & ethanoic acid
u find n moles of each reactants.
So
n(ethanol) = m/Mr = 30/46 = 0.65mol
n(ethanoic acid) = m/Mr = 30/60 = 0.5mol
As 1mol of reactants give 1 mol of ester
Ethanol is in excess, so all of it will not b used to make ester
But ethanoic acid will b used up fully (limiting reagent)to make that ester
So use the ethanoic acid
n moles acid = n moles ester. Find the theoretical mass of ester
theo. mass of eser = Mr x n ; actual m = 30g
Then, % yield= (actual m / theo. m) x 100%
I hope this is right! :o
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Man put up the question...there will b less confusion!! heres the question:
16 Compound X on refluxing with aqueous sodium hydroxide gave mixture Y which on distillation
with acidified potassium dichromate(VI) produced propanone. Mixing Y with dilute nitric acid and
aqueous silver nitrate gave a cream precipitate.
What could compound X be?
A CH3CHBrCH3
B CH3CHICH3
C CH3CH2CH2Br
D CH3CH2CH2I
Ok so ur right that is could C...since it has Br...which is the only 1 that gives cream ppt
But if u react choice C with NaOH u get a primary alcohol, right???
Then if u react that primary alcohol with dichromate u get a aldehyde & finally carboxylic acid.
But the question says that u get ketone(propanone)...which is the oxidation a secondary alcohol
So if u react choice A with NaOH u get Secondary alcohol as Br replaces OH on that 2nd C atom
Then that secondary alcohol gives ketone on oxidation....
I hope this proves its A.... :P
THANKYOU so much !!!
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Your welcome! 1up on my reputation power will b much appreciated!! ;D
Anyone figured out what questions will b repeated...in Chemistry paper 1 O/N 2009???
Which paper r rest of u guys taking - paper 11 or paper 12???
I'm gonna do paper 12 (9701/12)
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Taking /12 in 1 hr 30 min ;d
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Taking /12 in 1 hr 30 min ;d
Ditto
Good luck!
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WHAT A RETARDED PAPER. >:(
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HUH...u already gave the paper1/12/11??
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WHAT A RETARDED PAPER. >:(
Wht happened?? Just did paper 12.. its okAy.. ;)
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Wht happened?? Just did paper 12.. its okAy.. ;)
lack of sleep = fail :(
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Was it easy , hard or normal? any repeating questions from past papers?
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Was it easy , hard or normal? any repeating questions from past papers?
are you related to AS girl?
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No i have no idea who that it
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@ Lassst.. AS is DONE!!! Hey mani.. can you gimme the link for the P2 thread?