[Doctor.]

(Original post by StraightUpG)
im retaking it .. havent started revising for it yet ..

Fair enough, I did my revision ages back but it's a case of remembering it Not too good at that

Just did the Jan'12 paper, tricky but manageable lost a few marks because of silly stuff and got tricked lol

[StraightUpG]

(Original post by Doctor.)
Fair enough, I did my revision ages back but it's a case of remembering it Not too good at that

Just did the Jan'12 paper, tricky but manageable lost a few marks because of silly stuff and got tricked lol

well technically i revised in december then :P lol i got an A in the unit but im retaking it to try and get an A* but now i dna if i shud put more attention on my other subjects and even chem 5 so i think im gna leave chem 4 last minute and yeh jan 12 was trickey horrible NMR question :/

[Bright.Inspiration.]

(Original post by Doctor.)
Plenty of time to improve What topics you get wrong?

Nothing specific... like I just dropped a mark here and a mark there, making stupid mistakes lol.
Like I made some silly mistakes in one of the calcuations, and also the buffer question where you had to add amino-hydrochloric acid or someting like that XD

[Bright.Inspiration.]

(Original post by SoftMusk)
i stil dont get mass spec and nmr but im doing past papers on them....

The more questions you do, the more sense they make ... I go through the mark scheme step by step and I find this helps me understand how it's meant to be worked out

[sanaindaclub]

Whats the link between a diol and a diacarboxcylic acid and the linkage betweeb a diamine and a dicarboxcylic acid called?

[Bright.Inspiration.]

(Original post by sanaindaclub)
Whats the link between a diol and a diacarboxcylic acid and the linkage betweeb a diamine and a dicarboxcylic acid called?

between diol and dicarboxcylic acid it's an ester linkage

between diamine and dicarboxcylic acid it's an amide/peptide linkage

[Bright.Inspiration.]

(Original post by shuaib786)
Can you please explain the whole spilting pattern thing???

Basically if the carbon next to the one you're looking at has:
3 H atoms on it = then the splitting will be a guartet
2 H atoms = triplet
1 H atom = doublet

It's n + 1

[shuaib786]

(Original post by Bright.Inspiration.)
Basically if the carbon next to the one you're looking at has:
3 H atoms on it = then the splitting will be a guartet
2 H atoms = triplet
1 H atom = doublet

It's n + 1

Thanks I understood it when as i went through the past papers.

[Doctor.]

(Original post by Bright.Inspiration.)
Basically if the carbon next to the one you're looking at has:
3 H atoms on it = then the splitting will be a guartet
2 H atoms = triplet
1 H atom = doublet

It's n + 1

Do you mean quartet?

I hate proton NMR. It seems so simple, yet its so easy for a very seemingly different question to come up!

[I.LoveSyria.Aleppo]

What topics are most likely to come up on this exam?
Whats not on the past papers?

This was posted from The Student Room's Android App on my GT-S5830

[StraightUpG]

has chromatog ever come up?

[kontemptXD]

Chromatography has come up once, I remember a 4-6 mark question on chromatography in section B on one of the past papers. They also linked it in once on a question to do with the separation of amino acids after a dipeptide had been hydrolysed, only one mark though.

[Doctor.]

(Original post by StraightUpG)
has chromatog ever come up?

Only once!

(Original post by kontemptXD)
Chromatography has come up once, I remember a 4-6 mark question on chromatography in section B on one of the past papers. They also linked it in once on a question to do with the separation of amino acids after a dipeptide had been hydrolysed, only one mark though.

Don't think it was 6! More towards 3 I think i'll have a look tomorrow

[StraightUpG]

(Original post by Doctor.)
Only once!



Don't think it was 6! More towards 3 I think i'll have a look tomorrow

hmm got a feeling something like that will come up this time.. think boundries will be lower than or similar to jan 12

[Doctor.]

(Original post by StraightUpG)
hmm got a feeling something like that will come up this time.. think boundries will be lower than or similar to jan 12

I agree, think the grade boundaries will be similar to Jan'12

[swert]

http://store.aqa.org.uk/qual/gce/pdf...W-QP-JUN10.PDF

can someone help me with Q4 b how can you tell how many molecular ion peaks there are going to be :/

[Lola =]]

(Original post by swert)
http://store.aqa.org.uk/qual/gce/pdf...W-QP-JUN10.PDF

can someone help me with Q4 b how can you tell how many molecular ion peaks there are going to be :/

There are 4 chlorine atoms in that molecule therefore the possible combinations of chlorine atoms will be;
Cl-37 Cl-37 Cl-37 Cl-37
Cl-37 Cl-37 Cl-37 Cl-35
Cl-37 Cl-37 Cl-35 Cl-35
Cl-37 Cl-35 Cl-35 Cl-35
Cl-35 Cl-35 Cl-35 Cl-35
Therefore there will be 5 molecular peaks.

[nathaan5]

hi, in the spec it says 'be able to perform calculations for the titrations of
monoprotic and diprotic acids with sodium hydroxide, based
on experimental results' im stuck on this so can anyone offer any help!?

e.g In a titration we find that the equivalence point is reached when 25cm3 of 0.0150 mol dm-3 NaOH is neutralised by 15.0cm3 HCL. what is the conc of the acid?

and what else do we need to know for titrations? Thanks

[lochbeau]

Can anyone link me a paper with all correct answers and working for January 2012? Can't learn anything from a mark scheme... would be greatly appreciated.