OCR Chemistry A F324 Rings, Polymers and Analysis Tue 19 June 2012

hi how are you? you know in questions where they ask draw this structure can there be alternatives or only one specific structure? many thanks

and do you know a site with info on nmr proton and 13 carbon thanks

Have you tried knockhardy.org.uk or chemguide.co.uk? They're both brilliant sites for the OCR stuff

Hey guys, I'm doing this exam for the 4th time! I'm on my gap year and resitting my exams and this exam I just cannot do well in it! I learn the content inside out, do exam questions but the highest mark I got was a D. Where do you think I'm going wrong and what do you think I could do to improve my grade? It's really frustrating me that regardless of how much I work for this exam, my result never reflect the effort I've put in.

Hey guys, I'm doing this exam for the 4th time! I'm on my gap year and resitting my exams and this exam I just cannot do well in it! I learn the content inside out, do exam questions but the highest mark I got was a D. Where do you think I'm going wrong and what do you think I could do to improve my grade? It's really frustrating me that regardless of how much I work for this exam, my result never reflect the effort I've put in.

can anyone please explain or give me a useful link or video on hydrogen NMR to me, ive tried so hard to understand it but i just cant and also the role of TMS etcc

This is my third time, got a B first time round last Jan and then re did it since i was at a different college this jan and got worse on it despite working harder. How do you revise? And how many past questions do you do prior to sitting exams?




I'll try helping I'm okay'ish at it I think carbon NMR is hardest, As for TMS its nothing big it has 4 equivalent protons. (doing this on memory) It has a silane centre surrounded by 4 Methyl groups. Each of those are the same so only one would come appear on the NMR spectra. It does at Chemical shift 0 I think and it doesn't show on the graph so it'll never be shown on any Q's we do. Thats most you need to know about it. As for the main bit of H NMR itself which parts do you struggle with?


How's everyones revision going for this has everyone started? Or am I the only one behind with things!

This is my third time, got a B first time round last Jan and then re did it since i was at a different college this jan and got worse on it despite working harder. How do you revise? And how many past questions do you do prior to sitting exams?




I'll try helping I'm okay'ish at it I think carbon NMR is hardest, As for TMS its nothing big it has 4 equivalent protons. (doing this on memory) It has a silane centre surrounded by 4 Methyl groups. Each of those are the same so only one would come appear on the NMR spectra. It does at Chemical shift 0 I think and it doesn't show on the graph so it'll never be shown on any Q's we do. Thats most you need to know about it. As for the main bit of H NMR itself which parts do you struggle with?


How's everyones revision going for this has everyone started? Or am I the only one behind with things!

it is ok but im not understanding proton nmr and carbon 13 ! so confusing

i just find H nmr really hard

Hey guys! This is my 1st time doing this exam as my college have done it so we do F325 in January and F324 in the summer, and let me say, I do not like this unit -___- :L Organic is not my favourite (Y) Anyone agree? And, a lot of you guys seem to be resitting, so I was wondering if you had any tips for revision? That sounds bad, but anything you know you can do better with etc? Sorry if that doesn't make sense! Anyway, thanks, and good luck to everyone!

Carbon NMR is annoying and then they throw aromatic compounds at you and it gets harder! I think its more difficult than NMR. NMR is always difficult to explain I think the best way is just doing a few example Q's along with whats in the book I found that to be helpful. Some parts aren't so hard to explain like the N+1 rule which you use to get splitting patterns. The book has a few pointless things in it like spins which you don't need to know so ignore that.

What to remember is the number of peaks shows the number of proton environments. So say if the graph had 4 different peaks then theres 4 different proton environments. You can find out what these protons are bonded too by looking at the chemical shift on a data sheet. The more common ones are usually R-CH, O-H, COOH. Sometimes on top of the peaks you get numbers like here: http://lsc.ucdavis.edu/~holliste/jim118A/C5H12O2.GIF

this is known as the relative peak area and basically shows the number of protons in that environment. So sometimes you can use that to help you work out more about the compound analyzed. What to watch out for is protons which are sometimes equivalent they can catch you out. You use the N+1 rule to work out the splitting patterns so if something has 3 hydrogens on its environment then the peak would be split four times to make a quartet. We can also use the splitting patterns from a graph to work out how many protons are in an environment so say if a NMR graph had a peak split 5 times. We'd just deduct 1 to get the number of protons in that environment which would be 4.

Sorry if my explanations are a bit wordy they might not be that good but I've tried to explain a few of the simpler things apologies if theres any mistakes in there if so someone please do correct me! Hope you understand it slightly better now and if not sorry!




I'd say the 3rd unit with H NMR and C NMR is pretty important you usually always get a big marker on H NMR and usually a few on C NMR. I'd say the rest of the units aren't too bad there pretty much flashcard things this exam always feels harder though since it has probably more theory than any of the others. Get on past papers too they'll help a lot especially on big markers on the first 2 units (always big marks on structure of benzene and stuff). Apart from that I'm not sure what else to suggest :/

Haaate F324, got a high D last time

Anyone got any tips for using the stuff on the data sheet for H NMR and C-13 NMR? I really have no idea and this is a big pitfall