7. Gases

If the partial pressure of a gas in a mixture has declined to one third of its initial value, what is the new partial pressure if the initial pressure was 90 kPa?

A gas mixture with a total pressure of 795 mmHg contains CO2 at 107 mmHg, Ar at 255 mmHg, and O2 at 184 mmHg. The mixture also contains helium gas. What mass of helium gas is present in a 12 L container at 298 K?

A mixture of 10.0 g of Ne and 10.0 g of Ar has a total pressure of 1.60 atm. What is the partial pressure of Ar in the mixture?

A gas mixture contains each of the following gases at the indicated partial pressures: N₂, 257 Torr; O₂, 189 Torr; and He, 107 Torr. What is the total pressure of the mixture?