Question

Of the following gases, ________ will have the greatest rate of effusion at a given temperature.

Answer 1

According to Graham's law, the rate at which gases effuse (i.e., how many molecules pass through the hole per second) is dependent on their molecular weight; gases with a lower molecular weight effuse more quickly than gases with a higher molecular weight. Hope it cleared your doubt

Answer 2

Of the following gasses, CH4 will have the greatest rate of effusion at a given temperature.