How to calculate molar mass

Jun 2013
17
0
Assuming that atmospheric air is a mixture of nitrogen and oxygen in the mole ratio 79:21 estimate the molar mass of air.
 
May 2010
491
8
molar mass of air

Basis- 1 mol of dry air

N2 = 0.79*28=22.12 gms
O2=0.21*32=6.72 gms
Mol Wt of mixture =28.84 gms