Question

Four gases were combined in a gas cylinder with these partial pressures: 3.5 atm N2, 2.8 atm O2, 0.25 atm Ar, and 0.15 atm He.

What is the total pressure inside the cylinder?____atm

What is the mole fraction of N2 in the mixture?____atm

Answer 1

This can be solved using Dalton's Law of Partial pressures. This law states that the total pressure exerted by a gas mixture is equal to the sum of the partial pressure of each gas in the mixture as if it exist alone in a container. In order to solve, we need the partial pressures of the gases given. Calculations are as follows:


P = 3.00 atm + 2.80 atm + 0.25 atm + 0.15 atm

P = 6.8 atm

3.5 atm = x (6.8 atm)

x = 0.51

Answer 2

The total pressure inside the cylinder is 6.7 atm

The mole fraction of N2 in the mixture is 0.52 atm