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AQA GCSE Chemistry - C2 & C3 (14th May 2015)

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Whats the link?

http://www.thestudentroom.co.uk/showthread.php?t=3327275&p=55803793#post55803793 --OFFICIAL THREAD AQA GCSE P2 & P3 Wednesday 20th May 2015

Reply 1381

Esther228

My school only taught us half of the C2 syllabus so it felt really under prepared for that exam, i mean of course i did revision on the topics that where not taught, but i still felt that there was some lack of knowledge that other students would have from a proper teacher.
i mean our school is so bad, last week i didn't get entered in for the IGCSE english resits, because i wanted to get an A, but nope, and only 6 out of 80 of us got left out.
but this chem test was really important because i did really badly on my Bio test

Reply 1382

MrTechGamer

Original post by JG12333

As the forward reaction is endothermic, increasing he heat will cause it to favour that side, to use up the extra Heat, so there will be a higher % yield.
So you were right.

Decreasing the temprature of the reaction will favour the exothermic reaction and produce a higher yield.The forward reaction to form Hydrogen Iodide was exothermic , so less temp = higher yield of Hydrogen Iodide.

Reply 1383

Muaaz98

Original post by BeccaSpillane

Anyone know when the c3 markscheme will be released?

10 days after the exam to teachers, but you can access it for free from AQA in about exactly 51 weeks from now LOL

Reply 1384

MrTechGamer

Can anyone possibly send a copy of the my gcsescience QandA documents ? , If so that would be great because I've lost my CGP rev guide when I took it for the morning chemistry exams today !

Reply 1385

Muaaz98

Original post by hangra97

Anyone have an unofficial mark scheme for C2?

Posted from TSR Mobile

http://www.thestudentroom.co.uk/showthread.php?t=3327991
Still hunting TSR for C3 Markscheme

Reply 1386

tman24

Original post by 11Jason11

Yes, and my teacher is a former AQA examiner, so I could forward you the e-mail...

Forward the email to me plz?

Reply 1387

Conor1998

Original post by ed_stacey

:bban:

:fuhrer:

:surprise: :ta:

:turban:

sadly no it's not olivia. The volumeS were cleArly stated and Thus you Are expected to add them up correctly with No variations. 25cm3 was given and so was the fact that 30cm3 of acid was added.

For C1 by the way; I predict a question on the use of jet fuel and its effect on steel beams, also bring in a compass because AQA sent out an email last week to bring one but not all schools could inform their students in time. Also I saw my teacher hiding the papers in a closet and I saw a first ever 12 marker so beware for that.

What!? A 12 marker?? That's inhumane and there is going to be so many people caught out by that compass thing if true.

Reply 1388

Conor1998

Original post by Muaaz98

http://www.thestudentroom.co.uk/showthread.php?t=3327991
Still hunting TSR for C3 Markscheme

If you find one hit me up

Reply 1389

JG12333

Original post by Pra99

Yeh less hydrogen iodide, more hydrogen and iodine as forward reaction is endothermic

Literally, I could cry right now, I've screwed up so many answers and was so confident about chemistry, Id be absolutely deighted with an A now.
So angry.
guess I'll just have to absolutely nail unit 1 then.

(edited 8 years ago)

Reply 1390

Sheena_G

Original post by olivialloyd

Did you have to put the 12 part? I completely forgot to add that bit :frown:

Maybe because theres other istopes of carbon like 16, but I don't know the mark scheme so maybe :smile:

Reply 1391

Palette

Original post by Nomes24

Ohhh right, don't worry, hopefully they won't want that much detail. I think I just put 3 proton, 4 neutron thing then the mass of a neutron and a proton is 1 each. Or maybe I did put relative atomic mass??! The brain trick thing is happening to me now xD

Hopefully we both got the A* for Chemistry. I wish you the best for Physics!

(edited 8 years ago)

Reply 1392

qwerzxcv1234569

Original post by 11Jason11

Unofficial Grade Boundaries

Chemistry Unit 2
A*= 47
A= 42
B= 36
C= 30
D= 26

Chemistry Unit 3
A*= 45
A= 39
B= 32
C= 26
D= 21

do you know the one for biology unit 2 and 3 aqua

Reply 1393

iKali

did you guys find c3 difficult?

Reply 1394

MrTechGamer

Original post by iKali

did you guys find c3 difficult?

I think the A* boundary will be aprox. 47 raw marks for C2 and for C3 it should be around 45 raw marks The exams were good but everyone is bound to make small silly mistakes even if all the knowledge is there , to prevent 100%

Reply 1395

qwerzxcv1234569

Original post by iKali

did you guys find c3 difficult?

i found unit 2 difficult i found unit 3 slightly easier

Reply 1396

Turtlebunny

Original post by Olivia197

Oh no- I thought it was asking about the backwards reaction because this produced the hydrogen iodide (can't remember what it was called) and so the yield of this would decrease because it is exothermic- how many marks would I lose?

Raising the temperature would favor the forward reaction as endothermic draws in energy. This means more hydrogen and iodine will be produced from the thermal decomposition of hydorgen iodide.

Reply 1397

11Jason11

http://www.thestudentroom.co.uk/showthread.php?t=3327275&page=3&p=55816911#post55816911 --OFFICIAL P2 & P3 THREAD

(edited 8 years ago)

Reply 1398

thomasconnor

Original post by Turtlebunny

Raising the temperature would favor the forward reaction as endothermic draws in energy. This means more hydrogen and iodine will be produced from the thermal decomposition of hydorgen iodide.

No it was asking about the backwards reaction as the forwards reaction was endothermic

Reply 1399

Turtlebunny

Original post by thomasconnor

No it was asking about the backwards reaction as the forwards reaction was endothermic

It asked whether increasing the temperature would have any affect on the amount of hydrogen iodide produced. They said the forward reaction was endothermic. Now read my answer, and you will see it is correct.