OCR B Salters - F335 Exam - 15 June 2011

I personally do not use chemical storylines ... I use a revision guide (cgp) that covers everything I need to know from storylines and chemical ideas.

But generally, you gain nothing from storylines

What does that mean? (Sorry) Bx

Hmm, that's what I did for AS but my teacher said they're running out of questions to ask so they're using storylines more :/ also, i'm doing past papers and there's a bit of storylines not covered in the revision guide

Hmm, that's what I did for AS but my teacher said they're running out of questions to ask so they're using storylines more :/ also, i'm doing past papers and there's a bit of storylines not covered in the revision guide

sorry I dont have the CGP... they try to make too many jokes and it just annoys me

In a few past papers I have come across questions similar and don't understand why the answer is what it is!

In a question such as
CH3OH(g) <=> HCHO(g) + H2 /\H = +80KjMol-1

It asks what the effect of raising the temperature would be on yield of HCHO.
I thought it would reduce the yield, as raising temperature favours the endothermic reaction, which is the reverse reaction, shifting equlibrium left.

However, the mark sheme says yield increases, as equilibrium moves in the endothermic direction.

Can someone please explain why this is the answer.

Thanks

My teacher advised giving them a passing glance before the exam, but overall the questions are on your chemical knowledge (as they should be =P) with some storylines aspects hidden in there.

the salters revision guide tells you the parts of storylines it doesnt cover.. so you could just read those parts

In a few past papers I have come across questions similar and don't understand why the answer is what it is!

In a question such as
CH3OH(g) &lt;=&gt; HCHO(g) + H2 /\H = +80KjMol-1

It asks what the effect of raising the temperature would be on yield of HCHO.
I thought it would reduce the yield, as raising temperature favours the endothermic reaction, which is the reverse reaction, shifting equlibrium left.

However, the mark sheme says yield increases, as equilibrium moves in the endothermic direction.

Can someone please explain why this is the answer.

Thanks

oops, looks like i'm overworking myself xD i'm becoming too paranoid and revising everything in detail.



i *just* saw that! i don't normally look at that part in detail lol, yeah it does state the sections we're examined on in the revision guide thanks

Also I've found this site:
http://www.4college.co.uk/a/index2.php
its quite good and it has the toolkits on them

Well better being paranoid than being too laid back (like me).

So what do you guys recommend doing at this stage? Reading the revision guide and doing past paper questions?

i'm finishing off oceans and then past papers for the whole day tomorrow

You have a university offer to meet!!!

(maybe?)