In a Gas Mixture of He, Ne, and Ar with a Total

Multiple Choice

In a gas mixture of He, Ne, and Ar with a total pressure of 8.40 atm, the mole fraction of Ar is ________ if the partial pressures of He and Ne are 1.50 and 2.00 atm, respectively.

A) 0.179
B) 0.238
C) 0.357
D) 0.583
E) 0.417