# Worksheet: Mole Fractions from Partial Pressures

In this worksheet, we will practice using Dalton's law to convert between mole fractions and partial pressures.

Q1:

A gas mixture used for anesthesia contains 2.83 mol oxygen, , and 8.41 mol nitrous oxide, . The total pressure of the mixture is 192 kPa.

What are the mole fractions of and ?

• A: 0.663, : 0.337
• B: 0.748, : 0.252
• C: 0.252, : 0.748
• D: 0.337, : 0.663

What are the partial pressures of and ?

• A: 48.3 kPa, : 144 kPa
• B: 64.6 kPa, : 127 kPa
• C: 127 kPa, : 64.6 kPa
• D: 144 kPa, : 48.3 kPa

Q2:

A mixture of hydrogen and oxygen gases is explosive if the oxygen content is more than .  In which of the following oxygen-hydrogen mixtures is the oxygen content closest to this threshold without exceeding it?

• AA hydrogen partial pressure of 199,000 Pa and an oxygen partial pressure of 6,200 Pa
• BA total pressure of 59.00 bar and an oxygen partial pressure of 1.500 bar
• CA hydrogen mass of 2.419 kg and an oxygen mass of 1.120 kg
• DA total pressure of 34.55 atm and a hydrogen partial pressure of 33.55 atm
• EA total mass of 921.3 g and an oxygen mass of 307.2 g