Question

Consider three 5-L flasks, fixed with pressure gauges and small valves, each containing 4 g of gas at 273 K. Flask A contains H₂, Flask B contains He, and Flask C contains CH₄. Compare the flasks' contents in terms of the characteristics listed. What can be said about the diffusion rate after the valve is opened?

a) Flask A will have the fastest diffusion rate.

b) Flask B will have the fastest diffusion rate.

c) Flask C will have the fastest diffusion rate.

d) The diffusion rates will be the same for all flasks.

Answer 1

According to Graham's law, the rate of diffusion or effusion of a gas is inversely proportional to the square root of its molar mass; hence, hydrogen (H₂) in Flask A, being the lightest gas, will have the fastest diffusion rate when the valve is opened.

Step-by-step explanation:

In this question, we're comparing the diffusion rates of three different gases: hydrogen (H₂), helium (He), and methane (CH₄), all at the same conditions in separate flasks. According to Graham's law of effusion and diffusion, the rate of diffusion is inversely proportional to the square root of the molar mass of the gas particles. Hydrogen, with the lowest molar mass, will have the highest rate of diffusion, while methane, with the highest molar mass, will have the lowest rate. Therefore, option (a) Flask A will have the fastest diffusion rate, is correct.