Which of the following gases has the lowest rate of diffusion?
[H=1.0, C=12.0, N = 14.0, O= 16.0]
Nitrogen
methane
Ammonia
Oxygen
Correct answer is D
The rate of diffusion of a gas is inversely proportional to the square root of its molar mass (Graham's law). This means that gases with a higher molar mass will diffuse more slowly than gases with a lower molar mass. Given the molar masses of the gases in the options, Oxygen (O=16.0) has the highest molar mass and therefore the lowest rate of diffusion