Nitrogen Compounds

Question 1

Preparation of amine (never seen before)

Answer 1

Reduction of nitrobenzene

Sn in excess con HCl, heat under reflux followed by addition of NaOH (aq)

Question 2

Neutralisation of amines with acids

Answer 2

ANY mineral acid

gives a salt

Question 3

Nucleophilic substitution with HX

Answer 3

limited R-X in ethanol, heat in a sealed tube

Question 4

Condensation to form amides

Answer 4

Anhydrous acyl chloride, RCOCl

Question 5

Electrophilic substitution of phenylamine

Answer 5

Aqueous bromine, decolourise orang aqueous bromine, white ppt formed

Question 6

Distinguish between phenol and phenylamine

Answer 6

Add neutral FeCl3 solution to each compound

Phenol forms a violet complex, phenylamine does not

Question 7

Acid hydrolysis of amides

Answer 7

Heat under reflux with aqueous H2SO4/HCl

Question 8

Alkaline hydrolysis of amides

Answer 8

Heat under reflux with Na/KOH (aq)

Question 9

Reduction of amides to form amines

Answer 9

LiAlH4 in dry ether only

Question 10

Test for primary amide

Answer 10

NaOH (aq) and heat

Gas evolved turns moist red litmus paper blue

Question 11

Test for ammonium salt

Answer 11

NaOH (aq) and warm

Gas evolved turned moist red litmus paper blue

Question 12

Test for amine

Answer 12

NaOH (aq), room temperature - no NH3 gas evolved