What is the partial pressure of Helium gas in a mixture of gases that contains 0.50 moles of helium, 1.5 moles of Argon, and 2.5 moles of Neon?
The total pressure of the mixture is 1.6 atm.

Question

Quizplus · Accepted Answer

1. Find the total moles of the gas mixture:

0.50 mol He + 1.5 mol Ar + 2.5 mol Ne = 4.5 mol total

2. Find the mole fraction of Helium:

moles of Helium/total moles = 0.50 mol/4.5 mol = 0.111

3. Use the mole fraction of Helium and the total pressure to calculate the partial pressure of Helium:

partial pressure of Helium = mole fraction of Helium x total pressure

partial pressure of Helium = 0.111 x 1.6 atm

partial pressure of Helium = 0.178 atm, which is closest to choice B (0.18 atm).

What Is the Partial Pressure of Helium Gas in a Mixture