A vessel contains 10.4 g of oxygen gas and 16.3 g of carbon dioxide. If the partial pressure of carbon dioxide gas is 1.84 atm, what is the partial pressure of oxygen gas (in atm)?

Answer 1

Refer to Daltons Law of partial pressures which tells us that the partial pressure of a gas is equal to the mole fraction times the total pressure. So, we have to find the mole fraction of oxygen.

moles oxygen = 10.4 g x 1 mol/32 g = 0.325 mol

moles CO₂ = 16.3 g x 1 mol/44 g = 0.377 mol

Total moles = 0.702 moles

Since the partial pressure of CO₂ is 1.84 atm, we can find the total pressure from Dalton’s law: mole fraction CO₂ x P_total = 1.84 atm

mole fraction CO₂ = 0.377/0.702=0.537

P_toral = 1.84/0.537 = 3.43 atm

Partial pressure oxygen= 3.43 - 1.84 = 1.59 atm