Question

80.0 liters of oxygen gas is collected over water at 50 degrees celcius. the atomsphereic pressure in the room is 96.00 kPA. what is the partial pressure of oxygen?

Answer 1

partial pressure O2 = total pressure - vapour pressure H2O at 50 deg C 
Vapour pressure H2O at 50 deg C = 12.332 kPa 
= 96.00 kPa - 12.332 kPa = 83.67 kPa