Question

the average molar mass of mixture containing 2 mole of O2 ,2 mole of N2 and 2 mole of unknown gas is 60g/mol what is molar mass of unknown gas​

Answer 1

average molar mass =( M1x1 + M2x2+M3x3 ) ............(1)

where M1 , M2 , M3 are the molar mass for O2, N2 and unknown respectively.

and x1, x2, x3 are mole fraction for O2, N2and unknown respectively.

so, M1 for oxygen= 16 g

M2 forNitrogen= 14 g

M3 = ??

x1= 2/(2+2+2) = 2/6

similarly x2 = x3 = 2/6

put in (1)

average molar mass =60

16×2/6 + 14×2/6+ 2×M3/6 = 60

5.33+4.67+0.33M3= 60

0.33M3 = 60 -10

M3 = 50/0.33

M3 = approximate 152