Question

180 ml of unknown gas is diffused in 15 minutes under identical conditions . 120 ml of sulphur dioxide is diffuses in 20 minutes.What is moleculer mass of unknown gas.​

Answer 1

Heya user!!

According to Graham's law of diffusion:

r1r2=√M2√M1

where

r = rate of diffusion

M = Molecular mass

r = Volume effusedtime=Vt

So,

r1r2 = √M2√M1⇒V1/t1V2/t2 = √M2√M1

⇒180/15120/20=√64√M1 (Molecular mass of SO2 = 64 g/mol)

⇒180×20/120×15 = 8/√M1 8×120×15180×20⇒√M1

On squaring both sides⇒M1 = 16

So, molecular mass of the hydrocarbon = 16 g/mol