Answer:
Explanation:
[tex]\frac{r_1}{r_2} = \sqrt{\frac{M_2}{M_1} }[/tex]
r₁ and r₂ are rate of diffusion of gas having molecular mass of M₁ and M₂
[tex]\frac{31.5}{30.5} = \sqrt{\frac{32}{M_1} }[/tex]
1.0666 = 32 / M₁
M₁ = 30
molecular weight of NO = 14 + 16 = 30
So the unknown gas is NO .