Question

A closed flask contains water at 70 deg C . The total pressure of the

air-and-water-vapor mixture is 500.0 torr. What is the partial pressure
(in torr) of the air in this flask? Use your book for the vapor
pressure of water at this temperature.

Answer 1

266.2 torr.

Step-by-step explanation:

A closed flask at 70°C contains a mixture of water and air. Part of the water is in the liquid state and part of it is in the gaseous state (water vapor). The total pressure of the flask is the sum of the pressure of the air and the pressure of the water vapor at 70°C.

P = Pair + Pwater

Pair = P - Pwater

Pair = 500.0 torr - 233.8 torr

Pair = 266.2 torr

The partial pressure of the air is 266.2 torr.