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Author Topic: CHEMISTRY PAPER 1 HERE  (Read 37867 times)

Offline GodOfWar

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Re: CHEMISTRY PAPER 1 HERE
« Reply #315 on: June 11, 2009, 09:40:38 pm »
aquous means dissolved in water or solution
molten means just melted, in pure liquid form
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Offline GodOfWar

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Re: CHEMISTRY PAPER 1 HERE
« Reply #316 on: June 11, 2009, 09:51:01 pm »
Quote from: sweetest angel on June 11, 2009, 09:30:54 pm
Quote from: cockyxrocker on June 11, 2009, 09:19:18 pm
Nov 2008 questions 15,20,29
help!..
15) C...if it absorbs 10 from 1000cm^3 then it would absorb twice as much of heat from 500cm^3 since volume is halved!
20)HCL + BaNO3-->HNO3+BACL ....therefore the acidic nitric acid decrease the pH and since barium reacts with chlorine,therfore no precipitate
29)metals donot have 6 in their outa shell and always form ionic compounds thus B

for 15 the answer is A not C since the reaction is enothermic !
buh i still dont get it how will the solution absorb more heat if it has been halved ???. This is what i made out of it: since one of th rectants is being halved you wud need only half the energy .
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Re: CHEMISTRY PAPER 1 HERE
« Reply #317 on: June 11, 2009, 10:53:26 pm »
Quote from: GodOfWar on June 11, 2009, 09:51:01 pm
Quote from: sweetest angel on June 11, 2009, 09:30:54 pm
Quote from: cockyxrocker on June 11, 2009, 09:19:18 pm
Nov 2008 questions 15,20,29
help!..
15) C...if it absorbs 10 from 1000cm^3 then it would absorb twice as much of heat from 500cm^3 since volume is halved!
20)HCL + BaNO3-->HNO3+BACL ....therefore the acidic nitric acid decrease the pH and since barium reacts with chlorine,therfore no precipitate
29)metals donot have 6 in their outa shell and always form ionic compounds thus B

for 15 the answer is A not C since the reaction is enothermic !
buh i still dont get it how will the solution absorb more heat if it has been halved ???. This is what i made out of it: since one of th rectants is being halved you wud need only half the energy .
It is just like physics. It takes double the amount of heat energy to increase the temperature of 1000 cm3 of water by 1 degree celsius, than to increase the temperature of 500, by 1 degree. Thus, if there is half the volume of water, and the same amount of heat, the temperature change will be double. Take an example of sharing money (assume, it is heat) between 10 children (assume its 1000 cm3 of water). If we half the number of children to 5 (volume decreased to 500), the amount of money each will get, will double (temperature increases). :)
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Offline Priceless

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Re: CHEMISTRY PAPER 1 HERE
« Reply #318 on: June 11, 2009, 11:15:28 pm »
wow i-insane....im soooo impressed...ur soooo smart.....n rely gud n effective eg.....

all da best 4 tom....Take care n cya :)
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Offline examfreak

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Re: CHEMISTRY PAPER 1 HERE
« Reply #319 on: June 11, 2009, 11:45:54 pm »
cud any1 plz xplain why is the answer for Q13 un nov. 2008 is B and not D?
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Offline cockyxrocker

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Re: CHEMISTRY PAPER 1 HERE
« Reply #320 on: June 11, 2009, 11:51:14 pm »
Quote
Quote from: GodOfWar on Today at 08:51:01 PM
Quote from: sweetest angel on Today at 08:30:54 PM
Quote from: cockyxrocker on Today at 08:19:18 PM
Nov 2008 questions 15,20,29
help!..

15) C...if it absorbs 10 from 1000cm^3 then it would absorb twice as much of heat from 500cm^3 since volume is halved!
20)HCL + BaNO3-->HNO3+BACL ....therefore the acidic nitric acid decrease the pH and since barium reacts with chlorine,therfore no precipitate
29)metals donot have 6 in their outa shell and always form ionic compounds thus B


for 15 the answer is A not C since the reaction is enothermic !
buh i still dont get it how will the solution absorb more heat if it has been halved . This is what i made out of it: since one of th rectants is being halved you wud need only half the energy .

It is just like physics. It takes double the amount of heat energy to increase the temperature of 1000 cm3 of water by 1 degree celsius, than to increase the temperature of 500, by 1 degree. Thus, if there is half the volume of water, and the same amount of heat, the temperature change will be double. Take an example of sharing money (assume, it is heat) between 10 children (assume its 1000 cm3 of water). If we half the number of children to 5 (volume decreased to 500), the amount of money each will get, will double (temperature increases).


thanks a lot! that really helped!
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Offline examfreak

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Re: CHEMISTRY PAPER 1 HERE
« Reply #321 on: June 11, 2009, 11:57:01 pm »
hello? cud any1 answer my q please?
one more =)q 36..why is it A? same year-->2008..thanx
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Offline shafiq_92libra

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Re: CHEMISTRY PAPER 1 HERE
« Reply #322 on: June 12, 2009, 12:02:46 am »
may june ryt?
well cos all da oders do produce carbon dioxide lol
plus da option for A is HCL + C
ders no oxygen involved so how wud it give co2
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Offline Priceless

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Re: CHEMISTRY PAPER 1 HERE
« Reply #323 on: June 12, 2009, 12:03:49 am »
ya 4 q13....itz lead cuz it says low in da reactivity series.....so lead is lower den sodium...n it has 2 b molten cuz if in solution....hydrogen ll b liberated instead of da metal itself.....wich wnt mach wid da ques

so itz B.....hope u understud.....Take care n all da best
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Offline examfreak

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Re: CHEMISTRY PAPER 1 HERE
« Reply #324 on: June 12, 2009, 12:09:16 am »
thank you both =) but shafiq, i meant nov not may/june... thanx anyway=)
appreciated:)
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Offline shafiq_92libra

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Re: CHEMISTRY PAPER 1 HERE
« Reply #325 on: June 12, 2009, 12:14:37 am »
oh lol its cos chlorination and filtration is for less  polluted water not for water polluted wid fertilizers
i think lol
its definately not chlorination as chlorination is only used to kill bacteria
bt im not sure why filtration cant b used 0_0
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Manifest Destiny

Offline examfreak

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Re: CHEMISTRY PAPER 1 HERE
« Reply #326 on: June 12, 2009, 12:18:34 am »
hmmm..that exactly wat i was wandering about....hmmm...it's okay thanx anyway:)
sry but i have got one more question:P..wat is meant by the "oxidation state"?
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Offline Feva

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Re: CHEMISTRY PAPER 1 HERE
« Reply #327 on: June 12, 2009, 12:59:43 am »
gah i forgot lots of what i studied for paper 3...

tried my best to recover :P but ehhh i dont care anymore .. last exam.. dont care if i mess up :D :P
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Offline angell

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Re: CHEMISTRY PAPER 1 HERE
« Reply #328 on: June 12, 2009, 01:41:17 am »
dont think that way - its 30% weightage dude!!
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Offline aquarian93

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Re: CHEMISTRY PAPER 1 HERE
« Reply #329 on: June 12, 2009, 01:46:11 am »
which salts are soluble in acids and which salts react with acids? ???
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