Amines

Question 0

Step 2

Answer 0

Tin (II) ions are oxidised to tin (IV) ions which reduces the -NO2 to -NH2

Question 1

Step 1

Answer 1

Tin reacts with conc HCl to produce tin (II) ions and H

Question 2

Step 3

Answer 2

Flask is cooled and NaOH is added to redissolve Sn(OH)4

Tin (VI) hydroxide is amphoteric and with excess alkali it produces soluble Sn(OH)6 2-

Question 3

Step 4

Answer 3

Water is added and steam distillation is used to separate the mixture of phenylamine an water.

Question 4

Why is the distillate initially cloudy?

Answer 4

It is an emulsion of phenylamine and water.

When the distillate is clear only water is left.

Question 5

Step 5 - Salting out

Answer 5

Powdered NaCl is added and the mixture is transferred to a separating funnel which is shaken well.

Question 6

Step 6

Answer 6

Ethoxyethane is added and shaken.

The layers are allowed to separate and then the lower aqueous layer is run off into a small beaker.

Question 7

Step 7 - solvent extraction

Answer 7

Further extraction of the aqueous layer with further portions is carried out.
The layers of ethoxyethane extracts are combined.

Question 8

Step 8

Answer 8

Potassium hydroxide is added to dry the ethoxyethane extract.
KOH is alkaline so reacts with any traces of HCl removing it.

Question 9

Step 9 - Distillation

Answer 9

Ethoxyethane is distilled off and finally phenylamine is distiller off between 180 and 185c

Question 10

What is used in industry ?

Answer 10

Iron is cheaper than tin

Question 11

NO2 –> NH2 ??

Answer 11

Reduction NaBoH4