Chemistry AS unit 1 15th may 2012.
Chemistry exam discussion - share revision tips in preparation for GCSE, A Level and other chemistry exams and discuss how they went afterwards.
-
- Reputation:
- Banned
- Posts: 119
- Warning points: 1000
Re: Chemistry AS unit 1 15th may 2012.It wasn't easy ... there were lot's of areas where you could have lost easy 1 markers ... I think the *Average* will be -5 from MCQ and -15 from section B, as many got different answers for calculations etc...(Original post by 117r)
Well I certainly hope so. I actually though it was quite hard - lots of sneaky questions. Just loads of people found it very easy... -
- Reputation:
- New Member
- Posts: 3
Re: Chemistry AS unit 1 15th may 2012.I think it was because the water was in a gaseous state rather than a liquid state, this would mean that the enthalpy change would be more exothermic as more energy is needed to form water in it's gaseous state.(Original post by greywarden)
hey guys what were ur answers for the one which asked ' why would this enthalpy change be wrong'
and the section A was really hard !! -
- Reputation:
- Junior Member
- Posts: 27
Re: Chemistry AS unit 1 15th may 2012.LOL I can't remember if there were any percentages that you needed to work out in that paper, but let's hope not :P(Original post by sumitbagri_94)
How much dyu need to get out of 80 to get a 100%? -
- Reputation:
- Junior Member
- Posts: 33
Re: Chemistry AS unit 1 15th may 2012.Err... 80/80 to get 100%. Fool.(Original post by sumitbagri_94)
How much dyu need to get out of 80 to get a 100%? -
- Reputation:
- Benevolent Member
- Location: Cambridge
- Posts: 832
Re: Chemistry AS unit 1 15th may 2012.Um, no... fool(Original post by 7even)
Err... 80/80 to get 100%. Fool.
To get 100% UMS you do not usually need more than 72. Highest it's ever been is 75 I think. -
- Reputation:
- Benevolent Member
- Location: Cambridge
- Posts: 832
Re: Chemistry AS unit 1 15th may 2012.Once again, he is referring to 100% UMS.(Original post by AmberJade123)
LOL I can't remember if there were any percentages that you needed to work out in that paper, but let's hope not :P
Well I hope so anyway lolz! -
- Reputation:
- Junior Member
- Posts: 58
Re: Chemistry AS unit 1 15th may 2012.Hi...urm..for the Hess's cycle question..I drew the arrows up! Because it said it was the enthalpy of formation, but we were given the values of enthalpy of combustion...also when it a combustion reaction CO2 is always produced as a gas but this time only CO and H2O was produced...so thats why I drew the arrows up...
Any chances id get any marks? My value was positive aswell :/
I kinda figured everyone put the arrows down...but im confused!
Please someone put me outta my misery! -
- Reputation:
- New Member
- Posts: 3
Re: Chemistry AS unit 1 15th may 2012.Unlikely since it was three marks and I am guessing the marks were for arrows pointing down, balancing and state symbols sadly. :/(Original post by shan94)
Hi...urm..for the Hess's cycle question..I drew the arrows up! Because it said it was the enthalpy of formation, but we were given the values of enthalpy of combustion...also when it a combustion reaction CO2 is always produced as a gas but this time only CO and H2O was produced...so thats why I drew the arrows up...
Any chances id get any marks? My value was positive aswell :/
I kinda figured everyone put the arrows down...but im confused!
Please someone put me outta my misery! -
- Reputation:
- New Member
- Posts: 22
Re: Chemistry AS unit 1 15th may 2012.No, thats ridiculous, they would not mark you down for not putting the + sign, thats too picky even for edexcel. 35Cl 35Cl would definitly get the mark as its just a one mark question.(Original post by 7even)
****. Chloride ions did have to have the '+' sign... That's always the case. I messed that up too, hopefully they don't take off a mark for every single answer you didn't include '+' in.. -
- Reputation:
- New Member
- Posts: 22
Re: Chemistry AS unit 1 15th may 2012.And yeh, i got the hess wrong too (as usual), but hopefully you get one mark for labelling enthalpy change 1 and enthalpy change 2, and i think if you get +607 you will still get at least one mark for the right number, just the wrong sign(Original post by shan94)
Hi...urm..for the Hess's cycle question..I drew the arrows up! Because it said it was the enthalpy of formation, but we were given the values of enthalpy of combustion...also when it a combustion reaction CO2 is always produced as a gas but this time only CO and H2O was produced...so thats why I drew the arrows up...
Any chances id get any marks? My value was positive aswell :/
I kinda figured everyone put the arrows down...but im confused!
Please someone put me outta my misery!
-
- Reputation:
- Junior Member
- Posts: 58
Re: Chemistry AS unit 1 15th may 2012.oh damn :/ :/ I was stuck on it for ages!!! Thinking whether its up or down(Original post by xRimaz)
Unlikely since it was three marks and I am guessing the marks were for arrows pointing down, balancing and state symbols sadly. :/
-
- Reputation:
- Junior Member
- Posts: 58
Re: Chemistry AS unit 1 15th may 2012.Oh..thanks..really hope we get atleast one mark!! Feel gutted...(Original post by pcforster)
And yeh, i got the hess wrong too (as usual), but hopefully you get one mark for labelling enthalpy change 1 and enthalpy change 2, and i think if you get +607 you will still get at least one mark for the right number, just the wrong sign
-
- Reputation:
- New Member
- Posts: 22
Re: Chemistry AS unit 1 15th may 2012.No, the question was asking which species made the different molecular ions due to being made of different combinations of the two isotopes of chlorine. So writing chlorine-35+ would be wrong. It was just looking for the two atoms that would make the molecular ions shown.(Original post by 7even)
****. Chloride ions did have to have the '+' sign... That's always the case. I messed that up too, hopefully they don't take off a mark for every single answer you didn't include '+' in..
