Edexcel A2 Chemistry Unit 4 26/01/12 PM

hydrolysis of a nitrile( in acidic conditions you get your carboxylic acid. in alkali conditions you get your salt, which you then further react with a h+ catalyst to get your cooh group),

hydrolysis of a hydroxynitrile which produces the cooh group and an ammonium ion

I can't find the June 2011 paper anywhere, could you guys link me please?

Found the June 2011 paper here: http://www.mediafire.com/?znfe2s81dn5tf6x

mark scheme: http://www.mediafire.com/?3vwr5thuri4jroa

Am i right in thinking there are 4 past papers for us for this exam? (Jan 2010, June 2010, Jan 2011 and June 2011)?

Guys, a bit of advice please!
I am taking 5 other maths modules this January and am only really starting revision for chem now, is there still enough time left do you think, and what do people reckon the best way to revise quickly is?

FML Do we have to know the mechanism for the hydrolysis of acyl chlorides (like it forms carboxylic acids).
We spent a whole lesson making notes on it. Wow it is SO hard!

Edexcel revision guide doesnt have it, CGP revision guide doesnt have it. George probably does.
Will go check.

nope it doesnt.
But the textbook doesnt have it either (official edexcel one).. but the cd (active teach) has it.. and we all basically were there like wtfffffff. Swear im going to fail hahaha

Hey guys, hope revision is all well

Firstly, in my cgp revision guide (pg 55) it shows a carboxylic acid being reduced to a primary alcohol when reacting the acid with H+. Shouldn't it be H^- ??

Because, when you are doing the mechnasim for the reduction of an acid to an alcohol, you draw the H^- attacking the carbon.

FML Do we have to know the mechanism for the hydrolysis of acyl chlorides (like it forms carboxylic acids).
We spent a whole lesson making notes on it. Wow it is SO hard!

We never deal with H- though. In all honesty I've never seen the mechanism for that, but I wouldn't have thought it was a H-.



Nope, just need to know the coniditions/products of all its reactions.

Great, we spent a whole hour going over this stupid mechanism haha fmllll.


How's revision?

Revision is going ok. i have a test on the further organic chemistry and spectroscopy shizzle tomorrow. last thing. Going to spend my frees and lunch tomorrow revising because I NEED to do well so my other teacher doesnt think im completely dim. I've had two lessons with him. ive done redox equations (unit 5) and a test of pH, buffers and stuff. Hated both parts.

Organic chem is amazing <3 :L
I hate spectroscopy though, well its okay but NMR is annoying..

probably not,but might need to justify the equation..

eg.

CH3CH2CN + 2 H20 ---> CH3CH2COOH + NH3

But yeah how is everyone's revision going? I have applied for medicine so a pretty nerve racking January at the minute

I am revising a lot! I got 264/300 in AS, so I am aiming for an A* (I wont get it).

Right challenge time: Try not to use your books etc but im not forcing anyone if they want to...

I want a buffer of pH 4. Using ethanoic acid and sodium ethanoate, calculate the ratio of acid to salt needed. Ill make up Ka for the acid, which if I remember correctly is, 1.75 x 10^-5moldm^3


Rep+ please if you think it is a good question.

Answer is here in white

Rearranging Ka so that you have Ka over H+ conc = salt over acid

This is your ratio and it is: 0.175 moles of salt to every 1 mole of acid i.e. Ka over H+ conc = 0.175

But yeah how is everyone's revision going? I have applied for medicine so a pretty nerve racking January at the minute

I am revising a lot! I got 264/300 in AS, so I am aiming for an A* (I wont get it).

Right challenge time: Try not to use your books etc but im not forcing anyone if they want to...

I want a buffer of pH 4. Using ethanoic acid and sodium ethanoate, calculate the ratio of acid to salt needed. Ill make up Ka for the acid, which if I remember correctly is, 1.75 x 10^-5moldm^3


Rep+ please if you think it is a good question.

Answer is here in white