Question

if the mass ratio of hydrogen gas is to oxygen gas in a mixture is 1:2 then the ratio of their number of molecules is:

• A. 4:1
• B. 1:2
• C. 8:1
• D. 1:4

Answer 1

Answer: (C)

8:1

No of molecules = $\frac{Weight}{GramMolecularWeight}\times N_A$

Molecular wt of hydrogen $H_2$ = 2

Molecular wt of oxygen $O_2$ = 32

So Ratio of number of molecules = $\frac{1}{2}:\frac{2}{32}$ = $8:1$

Option $C$ is correct.