A mixture of methane and ethane in the mole ratio of x:y has a mean molecular mass equal to 20. What would be the mean molecular mass of a mixture of the gases present in the ratio y:x?
Molecular mass of methane = 16
Molecular mass of ethane = 30
Mean molecular mass = 20 = 16x+30yx+y
On solving, x=2.5y
Mean molecular mass in the second case = 16y+30xx+y = 16y+30(2.5y)2.5y+y = 91y3.5y = 26