Amines and amides

Question 1

Melting and boiling point of amines

Answer 1

Higher than corresponding alkanes as alkanes only have dispersion forces, Lower boiling point than alcohol as oxygen is more electronegative than nitrogen meaning the hydrogen bond isn’t as strong in amines, As chain length increases, so does boiling point

Question 2

Solubility of amines in water

Answer 2

Small amines are soluble in water as they form hydrogen bonds, As chain length increases, solubility decreases due to stronger dispersion forces

Question 3

Solubility of amines in organic solvents

Answer 3

Small amines are not very soluble in organic solvents, As chain length increases, solubility increases due to increased dispersion forces

Question 4

Odour of amines

Answer 4

Rotting fish

Question 5

Strength of amines

Answer 5

Weak bases (weaker than ammonia), RNH2 + H20 <—> RNH3+ + OH-, As chain length increases, basicity decreases (becomes weaker) as it doesn’t ionise as much

Question 6

Reactions of amines

Answer 6

React with acids (reversible reaction)

Question 7

Production of amides

Answer 7

Produced through a reaction of an amine with a carboxylic acid, How proteins are formed in nature, Used to form polymers in industry

Question 8

Melting and boiling points of amides

Answer 8

Higher than carboxylic acids as they can form more hydrogen bonds than carboxylic acids, As chain length increases, melting and boiling point increases

Question 9

Solubility of amides in water

Answer 9

Small primary amides are soluble in water, As chain length increases, solubility decreases due to increased dispersion forces

Question 10

Solubility of amides in organic solvents

Answer 10

Small amides are not very soluble in organic solvents, As chain length increases, so does solubility due to increased dispersion forces

Question 11

Chemical properties/reaction of amides

Answer 11

Neutral meaning they don’t accept or donate a proton