Question

A volatile liquid with vapor pressure 85 kPa (at sea level, 25° C) is taken to the peak of Mt. Everest. Which of the following is true?

(a) The vapor pressure of the solution decreases

(b) The solution will condense quickly than when at sea level

(c) The solution will vaporize quickly than when at sea level

(d) The vapor pressure of the solution increases

The question was posed to me during a job interview.

The doubt is from Vapour Pressure of Liquid Solutions in division Solutions of Chemistry – Class 12

Answer 1

The correct option is (d) The vapor pressure of the solution increases

For explanation I would say: The vapor pressure of a liquid is independent of the pressure of surroundings. Any solution boils when its vapor pressure equals the surrounding atmospheric pressure. The atmospheric pressure decreases with increase in altitude. Due to this, the vapor pressure equals the atmospheric pressure in a shorter period of time when compared to at the solution being present at sea level. Therefore, the solution will vaporize quickly as the bowling point will reached faster.