offical AQA a level chemisty unit 4 thread

thanks I understand the basics of splitting but i'm really stuck on this question-
the reaction of but-2-ene with chlorine produces 2,3-dicholorbutane (C4H8CL2), the compund T also has an isomer C4H8CL2 produces a proton n.m.r spectrum which consists only of two singlets with an integration ratio of 3:1. Draw the structure of compound T. Can you help me please?

Theres 2 ways about reaction mechanisms, you could just remember them, drill them into your head. Or you could try and understand them.

I'll be honest, at A-level there isn't much clarity on why certain mechanisms occur. But if you for example are having problems with acylation, look at all of them, there is a pattern, learn it :P

Its not easy, but its rewarding

In effect all the acylation mechanisms are the same, but involve different reactants, e.g ammonia, amine, alcohol, water

Anyone got the mark scheme for the June 2010 paper? We had a mock on Thursday but our teacher said that she can't give us the mark scheme? All we got back was the question paper.

Could you post the paper please

Here it is

Thanks a lot
If I get hold of the MS I'll let you know

2 CH3 bonded to a C.

This C is bonded to a Cl

This C is also bonded to a CH2Cl group


We have two singlets and a integ ratio of 3:1


It's difficult to explain how u get there, but trial and error works for me just think about it logically, and double check your answers!!!

thanks I was thinking along the right lines..but I didn't think it was right.

C(CH3)2ClCH2Cl is the answer, but I don't understand how there can be 2 singlets. we have CH3 next to a hydrogen so must be a doublet and a hydrogen is next to a CH3 so there's a quartet:s

how? draw the molecule. There is no hydrogen atom on the adjacent carbon atom, there's a Cl molecule.

thanks I understand the basics of splitting but i'm really stuck on this question-
the reaction of but-2-ene with chlorine produces 2,3-dicholorbutane (C4H8CL2), the compund T also has an isomer C4H8CL2 produces a proton n.m.r spectrum which consists only of two singlets with an integration ratio of 3:1. Draw the structure of compound T. Can you help me please?