ocr a f325 revision thread

What about it?

Wtf, if you add that to the half equation they give you, you get

CH3OH + O2 --> H2O + 2H+ + 2e- + CO2

Doesn't balance, neither do charges? Edit: Nvm it does balance I'm blind.

Can someone shed some light on how you do it please?

4bii http://ocr.org.uk/Images/65361-question-paper-unit-f325-equilibria-energetics-and-elements.pdf

the other 2 people got the same answer but its different to the mark scheme and we cant figure out why its wrong.

I felt that June 2012 was awful.

what parts did you find hard? have you dont the january 2013, it was much easier than that.

Well you have to multiply the oxygen half equation by 1.5 to get 1.5O2 and you go from there and you get the mark scheme answer

why would you multiply it by 1.5?

Well you have to multiply the oxygen half equation by 1.5 to get 1.5O2 and you go from there and you get the mark scheme answer

oh dear, sent the email for nothing.

Of course. Very nice.

no problem

Thanks. You've made it really clear.

Also just to confirm, CuCl4 wouldn't react with aqueous silver nitrate since they're also covalently bonded?

I have another question (not related to this one), if you or anyone else can explain would be awesome ;

So in a fuel cell, say a Ni(s) and Ni2+(aq). Why does the Ni(s) gain or lose mass? I really don't understand it.

I mean surely the only transfer we have are electrons but the mass of electrons are pretty much negligible so how is it possible we even have a measurable change in mass?

what is a use of the trans-platin?

How long is everyone taking to complete these papers roughly?

Any tips for working faster in this exam? Timing always gets me - erghhhh

I don't even finish them :P

what is a use of the trans-platin?

For copper and HNO3 reaction

copper is oxidised and Nitrogen is reduced

the half equation for copper

is it

Cu(s) ---> Cu2+ + 2e-


e- + NO3- + 2H+ ---> NO2 + H20 ?

you mean cis-platin? Anti-cancer drug?

yeah