26.3 Carboxylic acids and esters

Question 1

What two functional groups do carboxylic acids have

How does this impact the properties

Answer 1

C=O carbonyl group

and OH hydroxy group

The OH in carboxylic acids is much more acidic than the OH group in alcohols

Question 2

When naming carboxylic acids, if the functional group is on a benzene ring how is it named

Answer 2

The suffix - carboxylic acid is used

SO eg benzenecarboxylic acid

Carbon of the functional group is NOT counted as part of the root

Question 3

Are carboxylic acids soluble in water

Answer 3

They can form hydrogen bonds with water molecules due to the OH

So carboxylic acids up to butanoic acids are soluble

Question 4

Describe boiling points of carboxylic acids

Answer 4

High boiling points in solid state because the molecules form hydrogen bonds with each other

So higher BP than alkanes and alkenes of same mr

Question 5

What can be used to measure boiling points of carboxylic acids

Answer 5

Thiele tube

Or it can be found electrically

Question 6

What are esters

Answer 6

They are derived from carboxylic acids and alcohols reacting

RCOOR is general formula so C is connected to an oxygen in single bond, holding the two parts of the molecule together and also to oxygen in a double bond

Question 7

How are esters named

Answer 7

Based on name of parent acid, so all esters from ethanoic acid are called ethanoates

So methyl ethanoate is made from methanol and ethanoic acid

Question 8

What are short chain esters used for

Answer 8

They are fruity and sweet smelling so are often used in perfumes

Also used as solvents and plasticisers

Fats and oils are esters with longer carbon chains