A mixture of krypton and hydrogen gases, at a total pressure of 692 mm Hg, contains 20.9 grams of krypton and 0.133 grams of hydrogen. What is the partial pressure of each gas in the mixture?

Partial pressure Kr → 546.1 mmHg

Partial pressure H₂ → 145.9 mmHg

Explanation:

To determine the partial pressure of each gas in the mixture we apply the mole fraction concept.

Mole fraction → Moles of gas / Total gas = Partial pressure / Total pressure

In this mixture: Partial pressure Kr + partial pressure H₂ = 692 mmHg

We determine the moles of each:

20.9 g / 83.80 g/mol = 0.249 moles Kr

0.133 g / 2 g/mol = 0.0665 moles H₂

Total moles: 0.249 moles Kr + 0.0665 moles H₂ = 0.3155 moles

Mole fraction Kr → 0.249 mol / 0.3155 mol = 0.789

Partial pressure Kr → 0.789. 692mmHg = 546.1 mmHg

Partial pressure H₂ → 692mmHg - 546.1 mmHg = 145.9 mmHg