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

Yes, most likely.

Your theory is correct however the question asked for how increasing the temperature would affect yield of hydrogen iodide, so I'm not sure you whether you would be credited? I'm not an examiner though, sorry... It's only 2 marks so don't worry yourself.

Sorry when I reread I realised I'd put produced instead of used up. Basically if the endothermic reaction is favoured to lower the temperature, more hydrogen and iodine are produced as this is the endothermic reaction. If more hydrogen and iodine are produced, the hydrogen iodide would go down as more would be used up as the reactant in the endothermic reaction. Additionally as the endothermic reaction is favoured, the exothermic reaction which produces hydrogen iodide would go slower so less hydrogen iodide would be produced.

Don't worry about the grade boundaries. I'm sure many people found the equilibrium questions challenging, and there were a lot of them- should be fine.

Ok , lol i think i revised too much and mixed up mark scheme answers , some questions i didn't reread which is a bad habit lol , im probably gonna get a or something though due to annoying mistake i made with the 5 marker ! , not even on spec.

I must have written 'no', and then contradicted myself by talking about how equilibrium is restored as more of the backwards reaction takes place to counteract increase in temperature. I was probably thinking of the Haber process there.

Just a genuine mistake, no biggie so don't worry about it!

Nonetheless, I think I did very well in Unit 2 and I should focus on the Science Unit 1s and Physics now... and English Literature, which I'm clueless about.

Sounds good! What board are you on for English Lit? I'm doing AQA iGCSE. Studying Romeo and Juliet!

I'm studying the normal GCSE, with An Inspector Calls and Of Mice and Men, like many other people who use TSR.

I'm studying the normal GCSE, with An Inspector Calls and Of Mice and Men, like many other people who use TSR.

Cool, I did To Kill a Mockingbird for my coursework whereas other people in my year did Of Mice and Men. Think my brother did the exact same as you. Good luck for Monday(?) !

same doing an inspector calls to): dreading the essay questions

Cool, I did To Kill a Mockingbird for my coursework whereas other people in my year did Of Mice and Men. Think my brother did the exact same as you. Good luck for Monday(?) !

Yes, most likely.

[1 mark] - For saying most likely that the yield/amount of Hydrogen iodide (the compound on the left) goes up.
[2 marks] - For saying that the forward reaction is endothermic, so if more energy is supplied to the reaction, this is encouraged and more products are produced, reducing the amount of hydrogen iodide - converse will probably be accepted as well: The backward reaction is exothermic, so supplying more energy won't encourage it anymore, and will actually reduce yield of hydrogen iodide.

Grade boundary predictions:

b2:43
b3:45

c2:48
c3:46

these are for a stars

Did anyone else find the 5 mark on C3 about titration seriously difficult? I've spoken to my chemistry teacher who has been teaching GCSE and A Level for 15 years and she said she didn't have a clue what they were after!

the yield decreases you ****ing idiot