[hwgw]

Hi,

I have a question where I am given a sample of a mixture of gases (C2HF5 and C2H3F3) and was told to find the volume percentage of one gas.

Pressure = 0.449 atm
T= 288.15 K
Density= 1.79 g/L

I have also found the average molecular mass to be 94.266 amu.

So how can i approach this question to find the volume percentage of C2H3F3?
Do i use PV=nRT?

Thanks

[Yggdrasil]

What's the molecular mass of C2HF5?  What's the molecular mass of C2H3F3?  What ratio of the two gasses gives an average molecular mass of 94.266?

[hwgw]

When asking for average molecular mass, is that (mass 1 + mass 2) / 2 ?

[Kryolith]

No. You need to solve two equations:

x*M(C₂HF₅)+y*M(C₂H₃F₃)=94.266 g/mol
x+y=1

x=percentage of C₂HF₅
y=percentage of C₂H₃F₃
M=molar mass
94.266 g/mol = average molar mass of the mixture

[hwgw]

Thanks, that was really helpful.

[Kryolith]

You're welcome