Esters Module 6 Flashcards
What’s the functional group of an ester?
-COO- (carbon double bonded to one oxygen, and single bonded to another oxygen
How do you make an ester and water from alcohols and carboxylic acids?
Heat them together in the presence of sulfuric acid catalyst
It’s an esterfication reaction
Reversible reaction, so need to heat under reflux and use fractional distillation to separate the ester from other compounds
How do you name an ester?
Look at the alkyl group that came from the alcohol (the bit single bonded to the oxygen) and add yl to end of it, eg ethane = ethyl
Look at bit from carboxylic acid (bit bonded to the carbon double bonded to the oxygen (include that carbon aswel)) and find the name of it and replace oic acid with oate, eg ethanoic acid = ethanoate
Put the 2 parts together, eg = ethyl ethanoate
How do you make an ester from alcohols and acid anhydrides (made from 2 carboxylic molecules which OH groups have undergone a condensation reaction)?
The acid anhydride is warmed with the alcohol
The products are an ester, and a carboxylic acid which can then be separated out by fractional distillation
What do you react to get an ester, and HCl?
Acyl chloride with an alcohol
2 ways esters are hydrolysed to form alcohols?
Acid hydrolysis:
Reflux the ester with sulfuric acid, and H2O, will produce a carboxylic acid and an alcohol
Base hydrolysis:
Reflux the ester with NaOH, to get a carboxylate salt (instead of H in OH group of carboxylic acid, it’s a Na) and an alcohol
