A certain volume of $CH X_{4}$ (molar mass 16) effuses through a hole in $50 s$ . The time in seconds (nearest integer) for the same volume of $He$ (molar mass 4) to effuse under identical conditions is

Numerical answer type, answer in s, tolerance 0.5.

Answer: 25 s

t \propto M

for equal volumes.

t_{He} = 50 \times \frac{4}{16} = 50 \times 0.5 = 25 s