OCR Chemistry A F325 Equilibria, Energetics and Elements Wed 13 June 2012

if you are talking about the rotate one well basically in olden days they used this sort of cylinder light thing. and they placed the isomers inside it and hit the light beam through the cylinder. the two isomers rotated it in opposite directions. just draw a picture of something like that. you don't need to know it but that's just how it worked.

These were the files that were uploaded to the website before some of the links became broken on transition metals, they probably aren't identical to the ones uploaded now with missing links but I suspect they're very similar

Help needed for Q7 part d (i) and (ii) for the june 2011 paper.

Help needed for Q7 part d (i) and (ii) for the june 2011 paper.

7di) When the cell is recharging, the redox reactions reverse - so they change sides.

That means the oxidation one is originally how it is and the reduction is the one to flip to the other side. And if you actually combined that way you'd notice it's the reverse of the original equation in part 7c.

Not sure on 7dii.

Hopefully that helps a little

Anyone have revision notes and practice for this exam?

http://chubbylemonscience.tumblr.com/

I found this girl's blog incredibly useful. You may have to dig through a few pages to get all of her revision notes for EEE as there are some for OCR Biology too.

I know this has been asked already, but does anyone have a link to the Jan 2012 paper? I tried a link earlier in the thread but it doesn't work. Could someone perhaps upload it directly to this thread? Thanks.

In other news today I came to the realisation that THIS EXAM IS SOOOOOOO HARD!!!!!

Here they are :

It's on here: http://www.thestudentroom.co.uk/misc.php?do=showattachments&t=1943168

anyone have the f325 january 2012 mark scheme? cannot find in anywhere!

Same, could someone please post the pdf file for the January 2012 F325 mark scheme.

The link doesn't work :-((

This exam is stupidly hard... n o idea why I am bothering to resit it. I found a brilliant guy on Youtube called Rich Thornly (http://www.youtube.com/richthornley#p/p he does amazing short videos about pretty much all of the topics for EEE.

June 2011 paper question 4e, the 'magic tang' buffers question

How did you decide which acid to choose, i.e. Why did it have to be lactic acid

Is the ratio of conjugate base to acid in a buffer solution always 1:1

You choose the acid with the pKa closest to the pH.

No the ratio varies a lot - there's quite a few past papers which test you on this.

Oh ok, but can you explain why you choose the acid with pKa closest to the pH

Thanks!