Carboxylic acids and derivatives

Question 1

Carboxylic acids are weak acids but will liberate CO2 from carbonates.

Question 2

Carboxylic acids and alcohols react, in the presence of an acid catalyst, to give esters.

Question 3

Common uses of esters

Answer 3

solvents, plasticisers, perfumes and food flavourings

Question 4

Vegetable oils and animal fats are esters of propane-1,2,3-triol (glycerol)

Answer 4

Glycerol can react with saturated (no double bonds) or unsaturated (at least 1 double bond) fatty acids

Glycerol + fatty acid —> fats and oils

Oil = type of ester

Question 5

Esters can be hydrolysed in acid or alkaline conditions to form alcohols and carboxylic acids or salts of carboxylic acids.

Question 6

How can soap be made?
What is the byproduct?

Answer 6

-hydrolysis of vegetable oils and animal fats
-react with NaOH
-glycerol = byproduct

Question 7

Define biodiesel

Answer 7

mixture of methyl esters of long-chain carboxylic acids

Question 8

How is biodiesel produced?

Answer 8

reacting vegetable oils with methanol in the presence of a KOHncatalyst

Question 11

Why are oils liquid at room temperature

Answer 11

-unsaturated hydrocarbon chains that aren’t straight
-can’t pack closely together
-low VDW
-low MP

Question 12

Why are fats solids at room temperature

Answer 12

-saturated hydrocarbon chains that are straight
-can pack together closer
-high VDW
-higher MP

Question 13

How can carboxylic acids be made from acyl chlorides

Answer 13

Reaction with water

HCl gas produced, toxic