Given that:
Mass of gas A, WA = 1 g
Mass of gas B, WB = 2 g
Pressure exerted by the gas A = 2 bar
Total pressure due to both the gases = 3 bar
As temperature and volume remain constant.
Now if MA and MB are molar masses of the gases A and B respectively, therefore
PAV = WART/MA
or, 2 × V = 1 × RT/MA ….. (i)
Also,
Ptotal V = (WA / MA + WB / MB)RT
3 × V = (1/ (MA + WB/MB)RT …….. (ii)
Dividing equation (ii) by (i), we get
Thus, a relationship between the molecular masses of A and B is given by 4MA = MB.