A given volume of methane diffuses in 20s. How long will it take the same…

A given volume of methane diffuses in 20s. How long will it take the same volume of sulphur (IV) oxide to diffuse under the same conditions?
[C = 12, H = 1, S = 32, O = 16

Correct Answer: Option C

Explanation

Relative molecular mass of CH₄ = 12 * 1 + 4 = 16
Relative molecular mass of SO₂ = 32 + 10 *2 = 64
tSO₂/tCH₄ = √MSO₂/MCH₄
t/20 = √64/16 = √4
t/20 = 2
∴ t = 20 * 2 = 40sec