5.3.3 Esters

Question 1

What is an ester?

Answer 1

A family of organic molecules which form when a carboxylic acid and an alcohol by losing an H2O molecule. The ester functional group -COO- joins the two carbon chains

Question 2

What is the general equation for the reaction to make an ester?

Answer 2

Carboxylic acid + Alcohol –> Ester + Water

Question 3

What is the structure of the name of an ester?

Answer 3

The alcohol becomes an …yl and the carboxylic acid becomes an …oate
e.g: propanoic acid + ethanol –> ethyl propanoate

Question 4

Why is esterification called a condensation reaction?

Answer 4

Water is produced as a by product of esterification

Question 5

What is the method of making an ester?

Answer 5

1. Mix carboxylic acid and alcohol together
2. Add sulphuric acid
3. Warm it
4. Tip mixture into sodium carbonate solution

Question 6

Why is sulphuric acid used making esters?

Answer 6

Acts as a catalyst

Question 7

Why is sodium carbonate used in making esters?

Answer 7

Neutralises the sulphuric acid catalyst which is very corrosive

Question 8

What are esters used for and why?

Answer 8

Esters are volatile with distinctive smells so are used for food flavourings and perfume