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AQA CHEM4 - 13th June 2012

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Reply 60
Original post by Glacier
I don't think the exam ever has organic synthesis questions with as many steps as that, and as thegodofgod pointed out, there is a much easier way to do that one.

I think it helps to remember common patterns, such as nucleophilic addition/substitution with C\equivN- if carbon chain increases by 1 etc.


Think i would be so screwed if that came up lol.

Really dont like it, doesn't help that no textbook has any questions on it either...:frown:
Reply 61
Original post by Doctor.
Think i would be so screwed if that came up lol.

Really dont like it, doesn't help that no textbook has any questions on it either...:frown:


Does your school have a subscription to Kerboodle online resources by Nelson Thornes? They have quite a few practice questions on synthetic routes.
Reply 62
Original post by Glacier
Does your school have a subscription to Kerboodle online resources by Nelson Thornes? They have quite a few practice questions on synthetic routes.


I don't go to a school.:frown: so no access to that
Reply 63
Original post by Doctor.
I don't go to a school.:frown: so no access to that

Oh, are you on a gap year then? I'll post the questions here if you want to have a go:

propan-1-ol \rightarrow 2-bromopropane

benzene \rightarrow phenylamine

ethane \rightarrow ethylamine

phenylmethanol \rightarrow methylbenzoate

bromomethane \rightarrow ethylamine

phenylamine \rightarrow N-(4-nitrophenyl)ethanamide

propene \rightarrow propanone

ethanol \rightarrow ethane-1,2-diol

Let me know if you want to check any of the answers. :smile:
Original post by Glacier
Oh, are you on a gap year then? I'll post the questions here if you want to have a go:

propan-1-ol \rightarrow 2-bromopropane

benzene \rightarrow phenylamine

ethane \rightarrow ethylamine

phenylmethanol \rightarrow methylbenzoate

bromomethane \rightarrow ethylamine

phenylamine \rightarrow N-(4-nitrophenyl)ethanamide

propene \rightarrow propanone

ethanol \rightarrow ethane-1,2-diol

Let me know if you want to check any of the answers. :smile:


Quick question, do you have to heat/reflux a secondary alcohol if you want to oxidise it to a ketone, or do you just have to heat it?
Reply 65
Original post by thegodofgod
Quick question, do you have to heat/reflux a secondary alcohol if you want to oxidise it to a ketone, or do you just have to heat it?

Kerboodle says that it should be refluxed, but I'm not sure if it's necessary since there's only 1 possible product. I'll have a look at some past papers later to see if there are any questions about this.
Reply 66
Original post by Glacier
Oh, are you on a gap year then? I'll post the questions here if you want to have a go:

propan-1-ol \rightarrow 2-bromopropane

benzene \rightarrow phenylamine

ethane \rightarrow ethylamine

phenylmethanol \rightarrow methylbenzoate

bromomethane \rightarrow ethylamine

phenylamine \rightarrow N-(4-nitrophenyl)ethanamide

propene \rightarrow propanone

ethanol \rightarrow ethane-1,2-diol

Let me know if you want to check any of the answers. :smile:


Aw that's awesome, I am going to start doing chem today so thanks so much!!! :h:
Reply 67
Just did the January 2012 exam as a mock, didn't do the best or anything :/. Missed some easy marks :frown:
Reply 68
Original post by Glacier
Oh, are you on a gap year then? I'll post the questions here if you want to have a go:

propan-1-ol \rightarrow 2-bromopropane

benzene \rightarrow phenylamine

ethane \rightarrow ethylamine

phenylmethanol \rightarrow methylbenzoate

bromomethane \rightarrow ethylamine

phenylamine \rightarrow N-(4-nitrophenyl)ethanamide

propene \rightarrow propanone

ethanol \rightarrow ethane-1,2-diol

Let me know if you want to check any of the answers. :smile:


Would really appreciate the answers to the ones in bold please :colondollar:

Think I am doing better on CHEM4 in general now, BUT I made a mess of tge Ph calculations in the mock paper I did :frown:
Reply 69
Original post by Doctor.
Would really appreciate the answers to the ones in bold please :colondollar:

Think I am doing better on CHEM4 in general now, BUT I made a mess of tge Ph calculations in the mock paper I did :frown:

phenylmethanol \rightarrow methylbenzoate

oxidation to benzoic acid (benzenecarboxylic acid) with K2Cr2O7/H+ and reflux, then esterification using CH3OH with conc. H2SO4 and reflux

phenylamine \rightarrow N-(4-nitrophenyl)ethanamide

acylation (nucleophilic addition-elimination) with CH3COCl to make N-phenylamide (remember that acylation with amines makes N-substituted amides), then nitration (electrophilic substitution) with conc. H2SO4 and conc. HNO3

ethanol \rightarrow ethane-1,2-diol

dehydration to ethene with conc. H2SO4 and reflux, then electrophilic addition with Br2 to make 1,2-dibromoethane, then reflux with NaOH (nucleophilic substition) to substitute both bromine atoms for OH groups

Original post by Doctor.
Just did the January 2012 exam as a mock, didn't do the best or anything :/. Missed some easy marks :frown:


That exam was a bitch of a paper :mad:

So unlike all of the previous Unit 4 papers.
Reply 71
Original post by thegodofgod
That exam was a bitch of a paper :mad:

So unlike all of the previous Unit 4 papers.

I'll be doing that paper tomorrow. Do you know where to get the examiner's report for it?

Original post by thegodofgod
Quick question, do you have to heat/reflux a secondary alcohol if you want to oxidise it to a ketone, or do you just have to heat it?


I had a look through some more past paper questions today and still haven't found anything about conditions for oxidising secondary alcohols. :frown:
Reply 72
Original post by thegodofgod
That exam was a bitch of a paper :mad:

So unlike all of the previous Unit 4 papers.


So true, overall it wasn't a MEGA HARD paper but just really different from normal. What got me was these little random 1/2 markers that were based off CHEM1 and 2.

Then I made some retarded mistakes on calculations :colondollar:.

Grade boundaries were unreasonably high tbh. Maybe a few marks lower to get an A*/cap
Reply 73
Original post by Glacier

phenylmethanol \rightarrow methylbenzoate

oxidation to benzoic acid (benzenecarboxylic acid) with K2Cr2O7/H+ and reflux, then esterification using CH3OH with conc. H2SO4 and reflux

phenylamine \rightarrow N-(4-nitrophenyl)ethanamide

acylation (nucleophilic addition-elimination) with CH3COCl to make N-phenylamide (remember that acylation with amines makes N-substituted amides), then nitration (electrophilic substitution) with conc. H2SO4 and conc. HNO3

ethanol \rightarrow ethane-1,2-diol

dehydration to ethene with conc. H2SO4 and reflux, then electrophilic addition with Br2 to make 1,2-dibromoethane, then reflux with NaOH (nucleophilic substition) to substitute both bromine atoms for OH groups


Thanks so much, feel silly I wasn't able to work It out now lol. The others were not too bad :smile:

Original post by Glacier
I'll be doing that paper tomorrow. Do you know where to get the examiner's report for it?



I had a look through some more past paper questions today and still haven't found anything about conditions for oxidising secondary alcohols. :frown:

Oxidising? Just under reflux and K2Cr2O7

From what I have seen, the organic synthesis isn't too bad in actual recent exam papers! Conditions are pretty relaxed/they really want to know reagents!
Original post by Doctor.
Thanks so much, feel silly I wasn't able to work It out now lol. The others were not too bad :smile:


Oxidising? Just under reflux and K2Cr2O7

From what I have seen, the organic synthesis isn't too bad in actual recent exam papers! Conditions are pretty relaxed/they really want to know reagents!


Glacier and I aren't sure whether or not to reflux, as reflux is normally used when there are 2 possible products, e.g. oxidising 1o alcohols.

Oxidising 2o alcohols only produces ketones, so we're unsure whether refluxing is needed :s-smilie:
Reply 75
Original post by thegodofgod
Glacier and I aren't sure whether or not to reflux, as reflux is normally used when there are 2 possible products, e.g. oxidising 1o alcohols.

Oxidising 2o alcohols only produces ketones, so we're unsure whether refluxing is needed :s-smilie:


oh I see! Well practically it doesn't matter If you do it to a ketone as there is no further oxidation possible.

So tbh, I would leave it out. It's not in either of the AQA endorsed textbooks from what I remember! Can't see it being on the MS either since its not really needed. They'll probably just use the list principal and mark It wrong if the marker is stupid :tongue:.
Original post by Doctor.
oh I see! Well practically it doesn't matter If you do it to a ketone as there is no further oxidation possible.

So tbh, I would leave it out. It's not in either of the AQA endorsed textbooks from what I remember! Can't see it being on the MS either since its not really needed. They'll probably just use the list principal and mark It wrong if the marker is stupid :tongue:.


Stupid examiners. :rolleyes:

Like examiners would ever be stupid.

Spoiler

Reply 77
Just did the January 2012 paper and made so many mistakes :mad:

Spoiler in case some people haven't done it yet and want to do it as a mock:

Spoiler

Reply 78
Original post by Glacier
Just did the January 2012 paper and made so many mistakes :mad:

Spoiler in case some people haven't done it yet and want to do it as a mock:

Spoiler



OMG firstly that's not bad.

Spoiler



Tbh when you actually think about it...you've not done too bad, a few mistakes which with a little more revision and you'll be on top!
(edited 11 years ago)
Reply 79
Original post by masterhr1
Does anyone have a link to a diagram/flowchart of all the organic synthesis route stuff?


being honest, it's best to just make one for yourself! You'll memorise it while you make it :h:

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