Question

The azeotropic mixture of water (b.p.100°C) and HCl
(b.p.85°C) boils at 108.5°C. When this mixture is distilled it is
possible to obtain
(a) pure HCl
(b) pure water
(c) pure water as well as pure HCl
(d) neither HCl nor H2O in their pure states

Answer 1

When the mixture is distilled it is possible to obtain neither the HCl nor H2O in their pure states.

• The azeotropic mixture of water is given as b.p. 100°C and that of Hcl is b.p.85°C, that boil at 108.5°C.
• It is an example of negative azeotrope where the boiling point is higher than either of the constituents in the azeotropic mixture.
• It is also called the maximum boiling mixture.
• When the mixture is distilled then neither HCl  or H20 can be obtained in their pure states.

Answer 2

Answer:

Sample 'B' will not freeze at 0°C because it is not pure water. At one atmospheric pressure, the boiling point of pure water is 100°C and the freezing point of pure water is 0°C.