AQA A level chemistry distillation

How does keeping the temperature of the reaction mixture below the boiling point of propan-1-ol ensure maximum yield of propan-1-ol obtained by distillation of a mixture?

Reply 1

jjeeeeeea

The aim of distillation is to boil off more volatile products (with a lower boiling point than propan-1-ol in this case). If you go over the boiling point of propan-1-ol, it will boil and evaporate - escapes before it can be condensed to a liquid. Doing this will reduce yield

Reply 2

Aeshakhan

Original post by jjeeeeeea

Thank you! And this might sound like a dumb question but how can propan-1-ol evaporate when we do distillation in a closed system? (bung on top)

Reply 3

jjeeeeeea

Original post by Aeshakhan

Thank you! And this might sound like a dumb question but how can propan-1-ol evaporate when we do distillation in a closed system? (bung on top)

Sorry, I was considering an open system - I think you can have both depending on which is safer for the particular reaction. The propan-1-ol will still evaporate in a closed system, but it condenses at the condenser and turns into the liquid distillate.
If you go too high, the yield is still reduced because the vapour can remain in the system and you need to make sure it doesn't vaporise to that extent. The impurities you are leaving are the LESS volatile ones that remain in the flask and the more volatile ones will be part of the distillate if they exist, you would have to use other purification techniques to remove those.