The vapor pressure of water at 20.0°C is 17.5 mm Hg.If the pressure of a gas collected over water was measured to be 453.0 mm Hg.What is the pressure of the pure gas?

Question

Quizplus · Accepted Answer

According to Dalton's law of partial pressures, the total pressure is the sum of the pressure of the vapor and the pressure of the gas. Therefore,
Total pressure = vapor pressure + pressure of gas collected
453.0 mm Hg = 17.5 mm Hg + pressure of pure gas
pressure of pure gas = 453.0 mm Hg - 17.5 mm Hg
pressure of pure gas = 435.5 mm Hg
Converting mm Hg to atm:
pressure of pure gas = 435.5 mm Hg / 760 mm Hg/atm
pressure of pure gas = 0.573 atm
Therefore, the best choice is C.

The Vapor Pressure of Water at 20