Question

A 250 mL sample of oxygen is collected over water at 25 degrees Celsius and 769 torr pressure. What is the pressure of the dry gas alone? (Vapor pressure of water at 25 degrees Celsius = 23.8 torr)

Answer 1

Dalton's Law

P tot = P H₂O + P gas

769 = 23.8 + P gas

P gas = 745.2 torr