Explanation: The rate of effusion for a gas is inversely proportional to the square-root of its molecular mass (Graham's Law). The gas with the lowest molecular weight will effuse the fastest. The lightest, and therefore fastest, gas is helium.

Which gas Effuses faster hydrogen or chlorine?

Graham's law of effusion states that the rates of effusion of two different gases vary INVERSELY as the SQUARE roots of the mass of their particles. M1 amd M2 are their respective relative molar masses. Hydrogen effuses approximately 6 times as fast as chlorine.

Which Effuses faster helium or argon?

Helium effuses faster than argon by a factor of 3.2 C. Argon effuses faster than helium by a factor of 10.