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Wjec AS Unit 2 Chemistry 27/05/22

How did the Unit 2 exam go for everyone?
Yeah I think it went pretty well thanks :smile: how did you find it?
Original post by Archock
How did the Unit 2 exam go for everyone?
Reply 2
Original post by likeastabiloboss
Yeah I think it went pretty well thanks :smile: how did you find it?

I found it to be a nice paper as well. I'm dropping a max of 14 marks from my calculations.

Any Q's you struggled on?

What'd you put for the equation where CH3COONa + CO2 + H2O was made? I wanted to put CH3COOH and Na2Co3 but then the equation wouldn't balance on the right side:/

And for the ∆H 4 mark question using q=mc∆T before this one I believe, where the Mr given was 126 did you subtract the Mr of Water from it? I was debating that but decided not to. Might've lost a mark on it.
I don't think there were any major problem questions, just a few strange 1 or 2 mark questions here or there that could be easy to lose marks on.

I put CH3COOH and NaHCO3 for that equation but I was debating it for a while tbh.

No I didn't think of that for the mcΔt question... good point though. It's kinda reassuring to feel like you can afford to drop some small marks so it should be ok👍

What papers do you have left?
Original post by Archock
I found it to be a nice paper as well. I'm dropping a max of 14 marks from my calculations.

Any Q's you struggled on?

What'd you put for the equation where CH3COONa + CO2 + H2O was made? I wanted to put CH3COOH and Na2Co3 but then the equation wouldn't balance on the right side:/

And for the ∆H 4 mark question using q=mc∆T before this one I believe, where the Mr given was 126 did you subtract the Mr of Water from it? I was debating that but decided not to. Might've lost a mark on it.
Reply 4
Original post by likeastabiloboss
I don't think there were any major problem questions, just a few strange 1 or 2 mark questions here or there that could be easy to lose marks on.

I put CH3COOH and NaHCO3 for that equation but I was debating it for a while tbh.

No I didn't think of that for the mcΔt question... good point though. It's kinda reassuring to feel like you can afford to drop some small marks so it should be ok👍

What papers do you have left?

Dang, I didn't even think of Hydrogen Carbonate :/ Well hopefully there was one mark for CH3COOH

Yeah I found it to be the same. 3-4 1-2 mark Q's were slightly tricky.

Main problem question for me was the last one for drawing the apparatus, I'm assuming I lost all 3, do you remember what you drew? 🤔

I have Physics Unit 2 and Math Unit 2 left.
Original post by Archock
Dang, I didn't even think of Hydrogen Carbonate :/ Well hopefully there was one mark for CH3COOH

Yeah I found it to be the same. 3-4 1-2 mark Q's were slightly tricky.

Main problem question for me was the last one for drawing the apparatus, I'm assuming I lost all 3, do you remember what you drew? 🤔

I have Physics Unit 2 and Math Unit 2 left.

Overall average, not as good as unit 1. Lost out guaranteed marks on the CH3COOH equation as I reacted it with NaOH instead of NaHCO3. Lost out marks on the E=MCdeltaT question as I used final temperature instead of increase in temperature for T that calculation, do you guys reckon I might lose the entire 4 marks for that calculation because of that mistake? Also what did you guys put for the name of another reagent that can be used for Test of alkenes? The paper definitely had its fair share of nice questions namely the 6 marker on rates of reaction and the 10 marker instrumental analysis. Lastly to answer Archock, for the last question I drew the diagram of the reflux, labeling round bottom flask, heat source and water inlets and outlets, labeling which way water came and which way it went out.
(edited 1 year ago)
Reply 6
Original post by Aspiringdentist6
Overall average, not as good as unit 1. Lost out guaranteed marks on the CH3COOH equation as I reacted it with NaOH instead of NaHCO3. Lost out marks on the E=MCdeltaT question as I used final temperature instead of increase in temperature for T that calculation, do you guys reckon I might lose the entire 4 marks for that calculation because of that mistake? Also what did you guys put for the name of another reagent that can be used for Test of alkenes? The paper definitely had its fair share of nice questions namely the 6 marker on rates of reaction and the 10 marker instrumental analysis. Lastly to answer Archock, for the last question I drew the diagram of the reflux, labeling round bottom flask, heat source and water inlets and outlets, labeling which way water came and which way it went out.


Don't worry, you will get ECF and only lose one mark for using Tfinal and not ∆T.

Yep, I definitely lost all marks then. My brain was kinda fried by the end lol. I was overthinking 'oxidation and reduction'.

Next time I will make sure to scan the whole paper for 3-4 minutes and start with easiest q's first.

That mc∆T question, you used the total mass of solution right? I.e 320 + 60g water. And, did you subtract the 3 Water molecules from the overall compound?

Second reagent I just said I2, since that should have a colour (grey, brown, yellow? Idk) in solution and when its added to alkene it will go to colourless, I2 is added electrophilically just like Br2.

I made a super stupid mistake on the end of the 10 mark Question due to the time pressure (of the exam) so probably 1-2 marks off. I put some stupid structure there with C with 5 bonds 😂 and 6H's instead of 4

I'm more confident on this one to be honest than Unit-1.
Original post by Archock
Don't worry, you will get ECF and only lose one mark for using Tfinal and not ∆T.

Yep, I definitely lost all marks then. My brain was kinda fried by the end lol. I was overthinking 'oxidation and reduction'.

Next time I will make sure to scan the whole paper for 3-4 minutes and start with easiest q's first.

That mc∆T question, you used the total mass of solution right? I.e 320 + 60g water. And, did you subtract the 3 Water molecules from the overall compound?

Second reagent I just said I2, since that should have a colour (grey, brown, yellow? Idk) in solution and when its added to alkene it will go to colourless, I2 is added electrophilically just like Br2.

I made a super stupid mistake on the end of the 10 mark Question due to the time pressure (of the exam) so probably 1-2 marks off. I put some stupid structure there with C with 5 bonds 😂 and 6H's instead of 4

I'm more confident on this one to be honest than Unit-1.


Yeah I was debating wether to use 320 g or 320 +60g for the mass, I stupidly ended up using 320, which I now think could be wrong, I actually didn’t subtract MR of H20 from the MR of the compound, which again could be wrong.
Honestly that question is the end of me..,,.

Also don’t worry about the structure of the compound in the 10 marker.
I left it out and came back to it in the end but ran out of time before I could draw the structure. Getting the structure right will only give you 1 mark, as long as you mentioned all the other key points you are gonna get 9 marks.

Question, In order to get an A* in overall A level chemistry, I know we need to get at least 90% UMS in unit 3, 4 and 5. What about unit 1 and 2 at AS, if we just get 80% UMS in both unit 2 and 1 at AS ( I,e minimum UMS for an A) could we still get an A* overall on the condition that 90% UMS is met for unit 3,4,5?

Hopefully I won’t need to, but if I miss out on 80% UMS for one of the units at AS could I choose to resit just that unit next year or do I have to resit both unit 1 and 2 if I do decide on resitting, thanks.
Reply 8
Original post by Aspiringdentist6
Yeah I was debating wether to use 320 g or 320 +60g for the mass, I stupidly ended up using 320, which I now think could be wrong, I actually didn’t subtract MR of H20 from the MR of the compound, which again could be wrong.
Honestly that question is the end of me..,,.

Also don’t worry about the structure of the compound in the 10 marker.
I left it out and came back to it in the end but ran out of time before I could draw the structure. Getting the structure right will only give you 1 mark, as long as you mentioned all the other key points you are gonna get 9 marks.

Question, In order to get an A* in overall A level chemistry, I know we need to get at least 90% UMS in unit 3, 4 and 5. What about unit 1 and 2 at AS, if we just get 80% UMS in both unit 2 and 1 at AS ( I,e minimum UMS for an A) could we still get an A* overall on the condition that 90% UMS is met for unit 3,4,5?

Hopefully I won’t need to, but if I miss out on 80% UMS for one of the units at AS could I choose to resit just that unit next year or do I have to resit both unit 1 and 2 if I do decide on resitting, thanks.

I'm curious about that too. Because I'm definitely going to retake Unit 1 Math and the ******ed unit 1 physics paper.

From the impressions I have, you should be able to resit Unit by Unit but I'm not too sure. I'd recommend that you ask your teachers.

Regarding UMS, I've got 0 clue how that's going to be calculated. Other than the fact that the UMS will come (for U1 and U2) after the grade boundaries are set and the grades are released at Aug 18.

Again, asking teachers is probably the best bet.

Regarding the question though, I'm pretty certain 380 was the right answer.

Considering it was 4 marks... One would be for correct values ∆T and another for Mass of solution (since both required minor calculations of + and -) then one for J -> kJ conversion (that seems unlikely so I was thinking it would be for substraction of Mr(H20)•3 from MRcompound) and lastly for the final answer of course in kJmol-1. The only substance for the third mark would be substraction of MrH2O or for value of energy in Joules .But they shift the marks around a bit every time so who knows :/
(edited 1 year ago)
Original post by Archock
Dang, I didn't even think of Hydrogen Carbonate :/ Well hopefully there was one mark for CH3COOH

Yeah I found it to be the same. 3-4 1-2 mark Q's were slightly tricky.

Main problem question for me was the last one for drawing the apparatus, I'm assuming I lost all 3, do you remember what you drew? 🤔

I have Physics Unit 2 and Math Unit 2 left.

Yeah I drew the same as Aspiringdentist6 for the reflux apparatus - mine ended up looking like some kind of vertical distillation.

Also, the chemistry past papers have been really good with ecf marks so hopefully that'll work out well for the -mcΔt question 😂 still can't figure out whether or not we needed to subtract the 3H2O from the compound.

I also said I2 for the alkene question but it was a complete guess.

I don't know how the UMS works out sorry, but the grade boundaries are going to be lowered this year because of COVID so it should average out overall:smile:
Reply 10
Original post by likeastabiloboss
Yeah I drew the same as Aspiringdentist6 for the reflux apparatus - mine ended up looking like some kind of vertical distillation.

Also, the chemistry past papers have been really good with ecf marks so hopefully that'll work out well for the -mcΔt question 😂 still can't figure out whether or not we needed to subtract the 3H2O from the compound.

I also said I2 for the alkene question but it was a complete guess.

I don't know how the UMS works out sorry, but the grade boundaries are going to be lowered this year because of COVID so it should average out overall:smile:


Well, I've thought about it now and I'm still confused lol. Because we were calculating ∆rH weren't we? And the H2O didn't actually participate in the reaction. So maybe we did need to remove it.

But then it was ∆H for every one mole of reaction then the compound includes water too since it was hydrated and so the water should be included in the one mole of the reaction... It's super confusing.

But it is kind of strange they chose a hydrated compound out of no where for this and that fact wasn't really use anywhere else in the question... So I'm still leaning more towards removal of H2O
Reply 11
Original post by Aspiringdentist6
Yeah I was debating wether to use 320 g or 320 +60g for the mass, I stupidly ended up using 320, which I now think could be wrong, I actually didn’t subtract MR of H20 from the MR of the compound, which again could be wrong.
Honestly that question is the end of me..,,.

Also don’t worry about the structure of the compound in the 10 marker.
I left it out and came back to it in the end but ran out of time before I could draw the structure. Getting the structure right will only give you 1 mark, as long as you mentioned all the other key points you are gonna get 9 marks.

Question, In order to get an A* in overall A level chemistry, I know we need to get at least 90% UMS in unit 3, 4 and 5. What about unit 1 and 2 at AS, if we just get 80% UMS in both unit 2 and 1 at AS ( I,e minimum UMS for an A) could we still get an A* overall on the condition that 90% UMS is met for unit 3,4,5?

Hopefully I won’t need to, but if I miss out on 80% UMS for one of the units at AS could I choose to resit just that unit next year or do I have to resit both unit 1 and 2 if I do decide on resitting, thanks.


I did some research and seems like we can choose units to resit. Have a look here:
https://www.wjec.co.uk/media/5hvfyjyd/wjec-entry-fees-2021-22-summer-english-17-12-2021.pdf page-23

Don't worry about the fees though, as long as whoever is in charge of exams/ 6th form thinks it's worth you doing it, it wouldn't cost you anything.
Original post by Archock
I did some research and seems like we can choose units to resit. Have a look here:
https://www.wjec.co.uk/media/5hvfyjyd/wjec-entry-fees-2021-22-summer-english-17-12-2021.pdf page-23

Don't worry about the fees though, as long as whoever is in charge of exams/ 6th form thinks it's worth you doing it, it wouldn't cost you anything.

Thank you!, reassuring to know that… again fingers crossed it won’t come down to that tho.

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