Chemistry 3B 09/05/2012
Chemistry exam discussion - share revision tips in preparation for GCSE, A Level and other chemistry exams and discuss how they went afterwards.
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Re: Chemistry 3B 09/05/2012I think you have to, since 2 mols of H2O were formed(Original post by solittletime)
I got +64.2 kJmol-1.. did we have to multiply by 2?? :O -
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Re: Chemistry 3B 09/05/2012(Original post by quintillion)
Does water bath qualify for an improvement?
You'd have to wipe the crucible pretty well when you reweigh it.
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Re: Chemistry 3B 09/05/2012****..(Original post by quintillion)
I think you have to, since 2 mols of H2O were formed -
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Re: Chemistry 3B 09/05/2012Are you sure thats the answer .. coz i got the same thing however some people are saying you need to multiply 2 .. i am confused .. what did u get for the percentage error??(Original post by solittletime)
I got +64.2 kJmol-1.. did we have to multiply by 2?? :O -
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Re: Chemistry 3B 09/05/2012i said electric heater .. so i suppose yes(Original post by quintillion)
Does water bath qualify for an improvement? -
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Re: Chemistry 3B 09/05/2012no you do not need to multiply by two, this is a common error.(Original post by avipsita)
Are you sure thats the answer .. coz i got the same thing however some people are saying you need to multiply 2 .. i am confused .. what did u get for the percentage error?? -
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Re: Chemistry 3B 09/05/2012for hess's? it is HCl(Original post by solittletime)
What was the acid we used? H2SO4 or HCl? -
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Re: Chemistry 3B 09/05/2012I have never came upon such thing(Original post by solittletime)
They gave the equation, didn't they?
If they used H2SO4, then you'd have to multiply by 2. But since they gave HCl, we don't have to.
basically we did not had to multiply by two, wether it is sulfuric acid or hydrochloric acid.
The reason why we did not had to multiply by two because we solved the questions before the hess's law, which used 2HCl, hence we already did. The only thing was asked to turn the second (delta H2) arrow to the other way and find delta Hr. -
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Re: Chemistry 3B 09/05/2012maybe ask a teacher about this :P(Original post by solittletime)
wait.. see what i attached.. i think we were supposed to multiply by 2...
basically we did not had to multiply by two, wether it is sulfuric acid or hydrochloric acid.
