[kickasskaz01]

Didn’t see any threads on this exam so thought I’ll make one any revision tips or just general thoughts on the exam please post.

[LilithSternin]

I'm in on this one we've got one brilliant teacher and one totally rubbish teacher, so I'm stressed about this exam already!

[kickasskaz01]

[otrivine]

(Original post by kickasskaz01)

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

[LilithSternin]

(Original post by otrivine)
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

[Tramp_kidnapper]

(Original post by LilithSternin)
Have you tried knockhardy.org.uk or chemguide.co.uk? They're both brilliant sites for the OCR stuff

Agreed I love Knockhardy's work sheets !

[the_alybot]

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.

[LilithSternin]

(Original post by the_alybot)
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.

Do you get stressed about exams? I know how frustrating and demoralising it can be when you work your socks off and it doesn't pan out the way you'd hoped have you tried doing literally every past question you can get your hands on? That's what worked for me with Unit F321. Hope you get on okay

[kimmey]

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

[atman7]

(Original post by the_alybot)
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.

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?

(Original post by kimmey)
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

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!

[otrivine]

(Original post by atman7)
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

[kimmey]

(Original post by atman7)
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!

i just find H nmr really hard

[LGrosvenor101]

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!

[atman7]

(Original post by otrivine)
it is ok but im not understanding proton nmr and carbon 13 ! so confusing

(Original post by kimmey)
i just find H nmr really hard

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!

(Original post by LGrosvenor101)
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!

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 :/

[kimmey]

(Original post by atman7)
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 :/

thanks very much that was usefuel i guess with those type of ques it just comes down to practice

[george08]

I hate chemistry at the moment!

[Smiley Face :)]

Is there a F325 version of this thread anywhere>??

[SpringNicht]

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

[clownfish]

(Original post by SpringNicht)
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

I suggest that you work through some of the examples with the marking scheme. The marks are given out in quite a fussy way eg if you work out what the compound is but don't write every single possible bit of working you will not get all the marks.

General rules for NMR:
1) No of H/C environments = no of peaks
2) Relative area of peak = no of H/C it represents
3) Nearby groups to the H/C = chemical shift (this is where the data sheet comes in, eg if the peak is at 1, then you write "R-C-H" and this means it's part of an alkyl group, if the peak is at 11, then you write "COOH" and this means it's the acidic proton of a carboxylic acid group)
Just for H NMR
4) Number of H on adjacent C to the C that the H itself it attached to = splitting pattern (n+1 rule - where n is the number of adjacent H, eg if a CH3 is on the next carbon to the with the H whose peak you are looking at, then the shape will be a quartet (3H+1 = 4))
5) Peak disappears in D2O = must be an acidic proton (OH or COOH)

[browb003]

Hi everyone, I've made some past paper question booklets that I can share with you

Also I've crudely put together a booklet on proton NMR (too big to upload to TSR )
NMR Booklet: http://www.datafilehost.com/download-6e281dbf.html
Mark scheme: http://www.datafilehost.com/download-241f9cf2.html