Question

A vessel contains three gases at these partial pressures: 100 torr oxygen, 300 torr helium, 200 torr neon

The mole fraction of helium is

0.10
0.50
0.33
0.17
none of these

Answer 1

The mole fraction of helium in a vessel that contain threes gases with a partial pressure of : 100 torr oxygen, 300 torr helium and 200 torr neon is 0.50

calculation

• mole fraction = partial pressure for helium divided by total pressure
• Total pressure=partial pressure of oxygen + partial pressure for Helium +partial pressure for neon

= 100+300+200=600

• mole fraction is therefore= 300/600= 0.50