<u>Answer:</u> The correct statement is gas A effuses faster than gas B.
<u>Explanation:</u>
To know the rate of effusion of gases, we use Graham's law.
Graham's law states that the rate of effusion of a gas is inversely proportional to the square root of the molar mass of gas. The equation that calculates the rate of effusion of a gas is given by:
As, rate of effusion is inversely related to the molar mass of the gas, so the gas which have less molar mass will effuse faster than the gas which have more molar mass.
Molar mass of gas A = 4 grams
Molar mass of gas B = 16 grams
Putting values in above equation, we get:
Rate of gas A is 2 times more than rate of Gas B. Hence, the correct statement is gas A effuses faster than gas B.