Deck 3: Esterification and dehydration of alcohols

Question 1

Generally, how is an ester formed?

Answer 1

An ester is formed when an alcohol is warmed with a carboxylic acid in the presence of an acid catalyst.

Question 2

Define esterification.

Answer 2

Esterification is the reaction of an alcohol with a carboxylic acid to produce an ester and water.

Question 3

Write out the reaction of propanoic acid with ethanol and name the product.

Answer 3

Question 4

Explain the apparatus and reaction conditions of an esterification reaction.

Answer 4

• Concentrated acid is often used as the acid catalyst.
• Inside the test tube a mixture of ethanol,ethanoic acd and sulfuric acid.

Question 5

Give a simple step by step method for preparing an ester.

Answer 5

• In a boiling tube, add 1cm^3 of the carboxylic acid to 1cm^3 of the alcohol. Add a few drops of concentrated sulfuric acid.
• Place the boiling tube n a hot water bath at about 80C for five minutes.
• Pour the product into a beaker of cold water.
• You will see an oil floating on the surface of the water. The oil is an ester.

Question 6

Define dehydration

Answer 6

Dehydration is an elimination reaction in which water is removed from a saturated molecule to make an unsaturated molecule

Question 7

What is needed for an alcohol to be dehydrated to form an alkene?

Answer 7

An alcohol can be dehydratedto form an alkene in the presence of an acid catalyst.

Question 8

What is the acid used to dehydrate alcohols?

Answer 8

• Phosphoric acid
• Sulfuric acid

Question 9

What sort of reaction is the dehydration of an alcohol an example of?

Answer 9

This is an example of a dehydration reaction.

Question 10

Draw the reaction for the dehydration of ethanol to form ethene and state an acid catalyst used.

Answer 10

CH₃CH₂(OH) —–> CH₂ CH₂ +H₂O