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

Answer;

B. Lower molar mass

Explanation; Diffusion or effusion is the process of particles of gases or fluids move from an area of high concentration to one of low concentration. The effusion rate depends on temperature, viscosity of the medium, and the size or mass of the particles. Gaseous particles tend to undergo diffusion because they have kinetic energy. Diffusion is faster at higher temperatures because the gas molecules have greater kinetic energy. According to Graham's Law of diffusion, the effusion rate of a gas is inversely proportional to the square root of the mass of its particles. Therefore; a gas with lower molecular mass will have a higher effusion rate compared to a gas with a higher mass.