The total pressure in a vessel containing hydrogen collected over water at 25degrees Celsius was 0.8atm. the vapor pressure of water at the temperature is 23.8torr. What was the pressure of the oxygen in torr?

Answer 1

Ptotal = pO2 + pH2O
You want p in atm?
Convert 23.8 torr to atm.
0.8 atm = pO2 + (23.8/760)
Solve for pO2.

You want p in torr?
Convert 0.8 atm to torr
0.8*760 = pO2 + 23.8
Solve for pO2.

Answer 2

p in atm?
0.8atm = pO2 +0.031
0.8-0.031 = pO2
0.769atm = pO2

p in torr?
608 = pO2 + 23.8
608-23.8 = pO2
584.2 torr = pO2