Calculate the mol fraction
A 2.50L container at 17.0 °C contains a mixture of three gases, N2, He, and CO2, at partial pressure of 0.32 atm, 0.25 atm and 0.4 atm respectively.
a) calculate the total pressure of the gas mixture.
What I've done for this is added up all the gas pressures to total 0.97 atm.
b) Calculate the mol fraction of CO2
This is where I need help, do I use PV=nRT to find the moles of CO2 ? and if so, what would be the next step?