Question

A gas container contains 35 gram nitrogen gas 64 gram O2 gas and .112 litre of CH4 at STP. What is average molecular weight of the gas mixture?

Answer 1

Answer:30.44 g mol^-1

Explanation:we have Mavg=M1X1+M2X2+M3X3

Where M1,M2,M3 is molecular weight,X1,X2,X3 is the mole fraction of components of gas mixture and Mavg is the average molecular weight.

Number of miles can be calculated as

nN2=35/28; nO2=64/32=20; nCH4=0.112/22.4=0.005

Moles fraction can be calculated as

XN2=1.25/(1.25+2+0.005),,

XO2=2/(1.25+2+0.005),,

XCH4=0.005/(1.25+2.0.005)

Therefore,

Mavg=28×1.25+32×2+16×0.005/3.255=30.44 g mol^-1