Question

A 500. mL sample of oxygen is collected over 20.0∘C water at 760. torr. If the vapor pressure of water at 20∘C is 23.8 torr, what is the vapor pressure of the dry oxygen gas?

Answer 1

Answer : The vapor pressure of the dry oxygen gas is, 736.2 torr

Explanation : Given,

Volume of sample of oxygen = 500 mL

Vapor pressure of oxygen + water = 760 torr

Vapor pressure of water = 23.8 torr

Now we have to determine the vapor pressure of the dry oxygen gas.

Vapor pressure of the dry oxygen gas = Vapor pressure of (oxygen + water) - Vapor pressure of water

Vapor pressure of the dry oxygen gas = 760 torr - 23.8 torr

Vapor pressure of the dry oxygen gas = 736.2 torr

Thus, the vapor pressure of the dry oxygen gas is, 736.2 torr