Ester reactions are reversible. How do you think you could convert an ester back into acid and alcohol?
An ester can be broken into carboxylic acid and alcohol by a process called "Hydrolysis". The reaction can be carried out in either acidic or basic conditions.
Hydrolysis under acidic conditions
The reaction of ester with water is very slow and is generally catalyzed by dilute acids, such as hydrochloric acid and sulfuric acid. The resultant breakdown of ester is a reversible reaction.
For example, ethyl ethanoate can be converted to ethanoic acid and ethanol as per the following reaction:
CH3COOCH2CH3 + H2O + Heat `harr` CH3COOH + CH3CH2OH (using aqueous acid)
An excess of water is used to complete the reaction as much as possible.
Hydrolysis under basic conditions
When carried out under basic conditions, the hydrolysis of esters is termed "Saponification" and is commonly used for formation of soaps from glycerol triesters in fats. The reaction is one-way, instead of reversible, and the products are easier to separate.
For example, ethyl ethanoate can be converted to parent carboxylic acid and ethanol using (aqueous) sodium hydroxide.
CH3COOCH2CH3 + NaOH + heat `->` CH3COONa + CH3CH2OH
Hope this helps.
You could do this conversion with a method called hydrolysis. Hydrolysis is a reaction by water. When carboxylic esters are combined with water, and added heat to, they react to the hydroxide ions. However, they do react differently under acidic and basic conditions.
If you would like to learn more, the attached link might help!