Which of the following leads to a higher rate of effusion?

a. cooler gas sample
b. lower molar mass
c. slower particle movement
d. reduced temperature

b. Lower molar mass.

Explanation:

∨ ∝ 1/√M.

where, ∨ is the rate of diffusion of the gas.

M is the molar mass of the gas.

As the gas has a lower molar mass, it will have a higher rate of effusion.

it should be p1 v1 = p2 v2