TOPIC : SOLUTIONS AND LIQUID STATES
Number of questions are 183, Select_Question:

QUESTION
Azeotropic mixture of water and HCl has the percentage of HCl. [AFMC 1997]




SOLUTION

Liquid mixture having a definite composition and boiling point is like pure liquid is called azeotropic mixture.An azeotrope or a constant boiling mixture is a mixture of two or more liquids whose proportions cannot be altered by simple distillation. This happens because, when an azeotrope is boiled, the vapour has the same proportions of constituents as the unboiled mixture. Hydrochloric acid as the binary (two-component) mixture of HCl and H2O has a constant-boiling azeotrope at 20.2% HCl and boiling point of mixture is 108.6 °C (227 &dge;F). Increased in boiling point of water due to H bond between Water and HCl, causing lowering of vapour pressure, or negative deviation from Raoult's law.
Answer: (a)