Qualification > Sciences
CHEMISTRY PAPER 1 HERE
cockyxrocker:
--- 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).
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thanks a lot! that really helped!
examfreak:
hello? cud any1 answer my q please?
one more =)q 36..why is it A? same year-->2008..thanx
shafiq_92libra:
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
Priceless:
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
examfreak:
thank you both =) but shafiq, i meant nov not may/june... thanx anyway=)
appreciated:)
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