Helium gas diffuses 4 times as fast as an unknown gas. What is relative molecular mass of the gas

The relative molecular mass of the gas : 64 g/mol

Given

Helium rate = 4x an unknown gas

Required

The relative molecular mass of the gas

Solution

Graham's Law

r₁=4 x r₂

r₁ = Helium rate

r₂ = unknown gas rate

M₁= relative molecular mass of Helium = 4 g/mol

M₂ = relative molecular mass of the gas

Input the value :

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be