How is the partial pressure of a component gas proportional to the percentage composition (by molar quantity) to the gaseous mixture?

1 Answer
Feb 14, 2017

The partial pressure of each gas is proportional to the given percentage.

Explanation:

PTotal=Pmethane+Pethane+Ppropane+Pbutane.

Given the Ideal Gas equation, PTotal=nTotalRTV

But nTotal=(nmethane+nethane+npropane+nbutane)

And so,

PTotal=(nmethane+nethane+npropane+nbutane)RTV

You have the percentage composition of the gas, and you simply multiply PTotal by the individual percentages to get the partial pressure of each gas.

Thus Pmethane=1.48atm×94%=??atm. And you can work out these pressures individually.

See here for another example.