esters Flashcards
What happens when an alcohol reacts with a carboxylic acid?
An ester is formed.
What is the functional group found in esters?
The functional group in esters is ‘-COO’.
How can esters be identified?
Esters have a distinctive fruity smell and are volatile (evaporate easily).
Why are esters useful in perfumes and food flavorings?
Because they have a fruity smell and are volatile, making them easy to use in scents and flavors.
What is the ester formed when ethanol reacts with ethanoic acid?
The ester formed is ethyl ethanoate.
What is required for the esterification reaction between an alcohol and a carboxylic acid?
An acid catalyst, usually concentrated sulfuric acid.
What happens during esterification?
Water is removed, creating the -COO ester bond between the alcohol and the carboxylic acid.
Why is esterification considered a reversible reaction?
Because the ester can be broken down by hydrolysis to produce the original alcohol and carboxylic acid.
How is an ester separated from the reaction mixture after it is formed?
For smaller esters, it can be distilled off because the ester is more volatile. For larger esters, fractional distillation is used after heating under reflux.
How are esters named?
The alcohol is named first, followed by the carboxylic acid. For example, butyl propanoate is formed from butanol and propanoic acid.
How can esters be made apart from alcohol and carboxylic acid reactions?
Esters can also be made by reacting an alcohol with an acid anhydride or an acyl chloride.
What is an acid anhydride?
An acid anhydride is formed by reacting two carboxylic acids together.
What happens when an alcohol reacts with an acid anhydride?
An ester and a carboxylic acid are formed, and the ester is separated by fractional distillation.
What are the products when an acyl chloride reacts with an alcohol?
The products are an ester and hydrogen chloride fumes.
What is hydrolysis of esters?
Hydrolysis is the reverse reaction where an ester reacts with water to form a carboxylic acid and alcohol.
