[sarshi02]

Hi,
Does anyone have a copy of the january 2012 f322 paper??
I would relaly appreciate it!! please!

[louisjevans]

Afternoon chemists ;D

I hate the 'suggest why..' questions, they frustrate me quite a bit -.-

But on a positive note, cations...

[louci]

hey guys
i am having trouble getting mod 4 into my head
any advice ???

[atman7]

(Original post by sarshi02)
Hi,
Does anyone have a copy of the january 2012 f322 paper??
I would relaly appreciate it!! please!

http://www.thestudentroom.co.uk/show....php?t=1943168

(page 2)

I think unit 3 is the biggest one people have trouble with. Green chem is big though too I think both will be the main focus on the paper. That being said I think most of this module is fairly easy it just gets slightly difficult from unit 3-4. How far has everyone gone with revision?

[Natalie21]

(Original post by louisjevans)
Afternoon chemists ;D

I hate the 'suggest why..' questions, they frustrate me quite a bit -.-

But on a positive note, cations...

Good evening fellow chemist

I cannot agree more hate the suggest why questions :/

[sarshi02]

(Original post by atman7)
http://www.thestudentroom.co.uk/show....php?t=1943168

(page 2)

i think unit 3 is the biggest one people have trouble with. Green chem is big though too i think both will be the main focus on the paper. That being said i think most of this module is fairly easy it just gets slightly difficult from unit 3-4. How far has everyone gone with revision?

thank u !! Ever so much!!!!!

[StayDENCH]

I Got This Exam!! Hope I Can Get A B-D... Because I Think Unit 1-Atoms, Bonds And Groups, Will F Me Over!!

[Natalie21]

Questions and answers anyone?

[SpringNicht]

Resitting this :/ Got 114 last time, need to get an A...

[narli]

(Original post by SpringNicht)
Resitting this :/ Got 114 last time, need to get an A...

what grade is 114

[narli]

(Original post by StayDENCH)
I Got This Exam!! Hope I Can Get A B-D... Because I Think Unit 1-Atoms, Bonds And Groups, Will F Me Over!!

unit 1 is a killer!

[SpringNicht]

(Original post by narli)
what grade is 114

B, 120 is an A, 105 is a B, 90 is a C etc

[Patchey1000]

Also a resitter anyone got any tips on how to do mass spec questions

[mathsclown]

(Original post by Patchey1000)
Also a resitter anyone got any tips on how to do mass spec questions

Process
Ionisation (knock off bonding electrons to form fragment ions)
Acceleration (electrically charged plates push ions to electromagnet)
Deflection (magnet pushes ions through a cured tube, smaller move quiker)
Detection (Ions are counted at each point at which they arrive at end of tube)

Results printed onto a mass spectra.
Mass spectra of an element: number of peaks indicates how many isotopes there are, you can use the graph to find the natural abundance of the isotope (peak signal/total of peak signals x 100)
Relative atomic mass can be found by (m/z isotope A x peak/total peak height) + (m/z isotope B x peak height/ total peak heights)

The peaks/signals can be used to try and figure out what compound entered the spectra, molecular ion is the heaviest ion and is to the furthest right (rmm of compound) and fragment ions are to the left.

Common fragment ions
Ch3+ m/z 15
C2H5+ and CHO+ m/z 29
CH3CH2CH2+ or (CH3)2CH+ m/z 43
C6H5+ m/z 77

[SpringNicht]

(Original post by Patchey1000)
Also a resitter anyone got any tips on how to do mass spec questions

Look at molecular ion peak and work out the most basic formula that would satisfy the chemical properties you know about. Then add CH2 and take off hydrogens as needed until you get the correct mass

Eg. You have an IR spectrum identifying your chemical as an alcohol, and you know the mass is 74 from the molecular ion peak.

You'd work out the mass of the most basic alcohol, methanol which is 32. You'd then add 14 (the mass of a CH₂) on until you get that (or with alkenes the closest you can to that, then take 2 hydrogens off for each double bond in there).

So 32+14=46 46+14=60 60+14=74

We have a CH3, OH, and 3 CH2s in there, so your chemical formula is C₄H₅OH

If you know whether it's a primary or secondary alcohol, you may then be able to work out the structural formula (in this example since it's a butanol of some sort, it can only be butan-1-ol or butan-2-ol and if we were told what it was oxidised to or something we could work that out)

[kimmey]

has anyone got the jan 2012 mark scheme ?

[clownfish]

(Original post by mathsclown)
Process
Ionisation (knock off bonding electrons to form fragment ions)
Acceleration (electrically charged plates push ions to electromagnet)
Deflection (magnet pushes ions through a cured tube, smaller move quiker)
Detection (Ions are counted at each point at which they arrive at end of tube)

Although this is all true and good stuff, you don't need to know it for OCR A. You just need to know that all the species on the mass spec have a positive charge.

[mathsclown]

(Original post by clownfish)
Although this is all true and good stuff, you don't need to know it for OCR A. You just need to know that all the species on the mass spec have a positive charge.

Thanks had a look at the syllabus and to be honest, there isnt much, extra stuff is just for understanding i guess! Shouldn't be too hard but hey never know what OCR will come out with

[mmasters]

Hi all,
I too prefer this unit to Unit 1. I managed to scrape a B in that, but looking to get an A in this. So far I've got all the mechanism and key reactions down as well as some definitions. How's your revision going so far?

[Stir fried Giblets]

(Original post by mmasters)
Hi all,
I too prefer this unit to Unit 1. I managed to scrape a B in that, but looking to get an A in this. So far I've got all the mechanism and key reactions down as well as some definitions. How's your revision going so far?

Thought it was going well, then I started doing a past paper so: ****