Chemistry AS Units 1 and 2 Organic

Which organic mechanisms do we need to know (for Edexcel AS Chemistry, Units 1 and 2)?

I know the electrophilic addition mechanism is needed, as are both (S_N1 and S_N2) nucleophilic substitution mechanisms. Do we need the elimination mechanism(s)? Esterification? Oxidation of alcohol to aldehyde/ketone/carboxylic acid?

For each reaction, we need rates (is it fastest with a primary, secondary, tertiary, longer alkyl chain, shorter alkyl chain, etc.) and conditions. Anything else?

And do we need physical trends in the organic groups (e.g. alcohols have higher boiling points than aldehydes, etc; primary alcohols have higher boiling points than tertiary alcohols, etc.)?

(edited 11 years ago)

Reply 1

joostan

Original post by Big-Daddy

Which organic mechanisms do we need to know?

I know the electrophilic addition mechanism is needed, as are both (S_N1 and S_N2) nucleophilic substitution mechanisms. Do we need the elimination mechanism(s)? Esterification? Oxidation of alcohol to aldehyde/ketone/carboxylic acid?

For each reaction, we need rates (is it fastest with a primary, secondary, tertiary, longer alkyl chain, shorter alkyl chain, etc.) and conditions. Anything else?

And do we need physical trends in the organic groups (e.g. alcohols have higher boiling points than aldehydes, etc; primary alcohols have higher boiling points than tertiary alcohols, etc.)?

Which board?

Reply 2

Big-Daddy

Original post by joostan

Which board?

Oh sorry, I should have specified - Edexcel.

Reply 3

joostan

Original post by Big-Daddy

Oh sorry, I should have specified - Edexcel.

Ahh I do AQA and need to know all of the above :s-smilie:

As for you its very long and i don't want to read it all so here you go:
Learn all on this :tongue:

http://www.edexcel.com/migrationdocuments/GCE%20New%20GCE/UA024832%20GCE%20in%20Chemistry%20Issue%204%20250510.pdf

Reply 4

Big-Daddy

Original post by joostan

Ahh I do AQA and need to know all of the above :s-smilie:

As for you its very long and i don't want to read it all so here you go:
Learn all on this :tongue:

http://www.edexcel.com/migrationdocuments/GCE%20New%20GCE/UA024832%20GCE%20in%20Chemistry%20Issue%204%20250510.pdf

What are all the mechanisms you need for AQA?

The Edexcel has some weird stuff I doubt you'll find anywhere else ... ever heard of the "O2 and O3 free radical substitution mechanism" or "discuss and explain, including mechanisms and the reactions involved, reasons CFCs are no longer used due to their damaging effect on the O3 layer"?

Reply 5

joostan

Original post by Big-Daddy

Yeah we got that.
Mechanisms:
Free radical substitution.
Elimination.
Nucleophillic substitution.
Electrophillic addition
Dehydration of alcohols using H₂SO₄

(edited 11 years ago)

Reply 6

Big-Daddy

Original post by joostan

Yeah we got that.
Mechanisms:
Free radical substitution.
Elimination.
Nucleophillic substitution.
Electrophillic addition
Dehydration of alcohols using H₂SO₄

Dehydration of alcohols is just leaving-group elimination isn't it?

What is my syllabus really asking for when it says "O2 and O3 free radical substitution mechanism" or "discuss and explain, including mechanisms and the reactions involved, reasons CFCs are no longer used due to their damaging effect on the O3 layer"? Anywhere I can find these online (because they aren't in my textbook)?

Reply 7

joostan

Original post by Big-Daddy

Yes but its a slightly different mechanism.
As for the rest provided you know the mechanisms the rest is common sense.
O₃absorbs UV radiation, without it the radiation can get through to the earth.

Reply 8

Big-Daddy

Original post by joostan

Yes but its a slightly different mechanism.
As for the rest provided you know the mechanisms the rest is common sense.
O₃absorbs UV radiation, without it the radiation can get through to the earth.

So what bond is being broken in the case of O3/O2 free radical substitution, and what are the radicals then substituting onto?

Reply 9

joostan

Original post by Big-Daddy

So what bond is being broken in the case of O3/O2 free radical substitution, and what are the radicals then substituting onto?

Cl^.for example attacks O₃ creating O₂ and OCl^.

Reply 10

Big-Daddy

Original post by joostan

Cl^.for example attacks O₃ creating O₂ and OCl^.

OK, and the destruction of O3 is "depletion of the ozone layer" with all these bad environmental effects that we keep hearing about, etc.

What is the relevance of CFCs? Just that they contain F and Cl which can then be made into radicals to make this process happen?