9 Carboxylic acids and esters

Question 1

carboxylic acids

Answer 1

functional group -COOH
contain carbonyl group and alcohol acid group

Question 2

acidity of carboxylic acids

Answer 2

weak acids - dissociate to form H+ ion and carboxylate ion, RCOO-

Question 3

bonding between carboxylic acids

Answer 3

hydrogen bonding between small molecules and water - between Hδ+ on acid and lone pair on oxygen in water

Question 4

making esters

Answer 4

react carboxylic acid and alcohol together with an acid catalyst

Question 5

uses of esters

Answer 5

perfumes, food flavourings, solvents, plasticisers

Question 6

hydrolysis of esters in acidic conditions

Answer 6

ester + water ⇌ carboxylic acid + alcohol

Question 7

hydrolysis of esters in alkaline conditions

Answer 7

ester + NaOH →carboxylate salt + alcohol

Question 8

lipid production

Answer 8

3 long chain carboxylic acids (fatty acids) joined through propan-1,2,3-triol (glycerol)

Question 10

how do soaps work?

Answer 10

they have a hydrophobic end (long chain hydrocarbon) which repels water and a hydrophilic end (short, ionic part) which attracts water

Question 11

biodiesel production

Answer 11

methylesters
lipid + 3CH3OH →3 methyl esters + glycerol
in presence of KOH catalyst