The Student Room Group

AQA Chemistry C3 - Unofficial Mark Scheme

Scroll to see replies

Original post by Roquebrune2014
I've just had a thought, for the energy change with specific heat capacity question, I put 3,444J but 4.2 is the SHC for water to change ONE gram of water, should 3,444 therefore be multiplied by 0.8 to scale it down to 0.8g from 1g?


Posted from TSR Mobile


That is how much for one gram, which is why you multiply by 50 as you have 50 one grams of water
Original post by mediaya
But then isnt an acid too stong as well? 😕


You can do it either way, acid into alkali or alkali into acid, it doesn't matter in general, but seeing as you were finding the concentration of the acid...
Reply 462
i just realised that i completed the balanced equation question in pencil. this is a really small thing to worry about but will it still get marked?
Original post by ivy_entoile
ISA borderline A/A*
C1 A
C2 again borderline A/A* but thinking about it, the boundaries will probably be quite high for this paper esp considering the 6marker so most likely on the A side
C3 C

i think overall that'd hopefully be a good A :crossedf::crossedf::crossedf:

As long as it's an A I'm fine fingers crossed hope you get what you want and same for everyone else out there. And when are the rest of the questions gonna be up!!😅
(edited 7 years ago)
Does anyone know what the effects are of the ISA grade like a low A* what does it do? lower the grade boundaries for u if ur aiming for a grade A or lower? Thanks!
Original post by milolj
Will you lose a mark for saying 1623 rather than -1623?
we did a similar practice question the day before and it said allow no minus sign
Reply 466
thank god. i thought i was the only one who did an exothermic reaction. did u get a positive answer for the bond enthalpy question?
Original post by mediaya
I got 212 and the bond question and after that they asked for why it was ENDOTHERMIC right? Everyone in my school got that.
We sat a different paper coz there is 2 specs
Further additional science unit 2, C3( the one i sat)
Chemistry, C3
Btw, what did everyone get for the balancing?? Was ethanol+oxygen making water and ethanoic acid?? Or was this question different as well coz i got 2,3,2?


Phew! someone who did the same exam as me, was worried they were the same exam as some questions are similar/same. I also got 212, and 2,3,2 for balancing, thank you so much you've saved my worries
you're supposed to divide the 3444J by 0.8g so its per 1gram
Reply 469
Original post by Account user
Does anyone know what the effects are of the ISA grade like a low A* what does it do? lower the grade boundaries for u if ur aiming for a grade A or lower? Thanks!


To get an A you need 320 UMS, which includes the ISA and all 3 papers (assuming you did triple).

With the ISA included (90 UMS), you'd need to make up 230 UMS across 3 papers which is roughly 77 UMS, so you need a high B or more on each paper to acheive an A grade :smile:
Thanks!!😃 So as I got 45(C1) 48(C2) and 30(C3) plus my ISA of 44 if it's an A and if it is an A according to last years grade boundaries how much marks would I be safe by (I'm still confused) 😂
Original post by hanzi12345
What is the source for methane?
i put cows.


I put crude oil and fracking
If more heat energy is released when making the bonds than was taken in when they broke, the reaction is exothermic.
Am so stupid cos i asked for extra paper in the exam and it asked for the date of the exam..... Guess what i put........ 14 june instead of 15!!!! 😑
Will the extra paper get marked or not?? 😓
Original post by arj2104
I put crude oil and fracking


I put crude oil too
Reply 475
Probably will. You have your candidate number, name and paper reference, and you've attached it to your exam so they should do @mediaya

Posted from TSR Mobile
Reply 476
Original post by Covcity5300
you're supposed to divide the 3444J by 0.8g so its per 1gram


Didn't it say how much energy is released for the 0.8g of fuel. Idk can't remember

Posted from TSR Mobile
Original post by dee08
Didn't it say how much energy is released for the 0.8g of fuel. Idk can't remember

Posted from TSR Mobile


Yeah it said for 0.8 grass I made sure
Original post by dee08
Probably will. You have your candidate number, name and paper reference, and you've attached it to your exam so they should do @mediaya

Posted from TSR Mobile


Thanks

Posted from TSR Mobile
Original post by surina16
Yeah I didn't know so I wrote air contains many gases and so these could react to form unwanted products or some bs :lol:


okay thanks :smile:

Quick Reply

Latest