A gaseous mixture containing 7.00 moles of nitrogen, 2.50 moles of oxygen, and 0.500 mole of helium exerts a total pressure of 0.900 atm. What is the partial pressure of the nitrogen?

Partial Pressure = 0.630atm

Explanation:

The total pressure of a mixture of gases is equal to the partial pressure of those gases. The partial pressure of a gas is defined as:

Partial pressure = Mole Fraction * Total pressure

The mole fraction of a gas is the ratio between the moles of the gas and the total moles.

To solve this question we need to find the mole fraction of nitrogen to find its partial pressure:

Mole Fraction nitrogen:

7.00 moles Nitrogen / (7.00moles N2 + 2.50moles O2 + 0.500moles He) = 0.700 = Mole fraction.

Partial Pressure = 0.700* 0.900atm