Answer :
To find the time required for 40 mL of oxygen to effuse, we use Graham's Law of Effusion, considering the molar masses and volumes of both hydrogen and oxygen. With the correct calculations, hence , the correct answer is B)32 minutes.
The question focuses on the diffusion of gases and references Graham's Law of Effusion, which states that the rate of effusion of a gas is inversely proportional to the square root of its molar mass. Given that it takes 20 minutes for 50 mL of hydrogen to effuse, we can determine the time required for 40 mL of oxygen to diffuse out by adjusting for the difference in the rate of effusion (due to their respective molar masses) and the volume of the gases. Since hydrogen effuses four times as rapidly as oxygen, we can set up a ratio to find the answer. The correct option is B. 32 minutes. This is calculated by considering the effusion rates and the volume of gas, using the formula t2 = t1 * (M2/M1)^0.5 * (V2/V1), where t1 and t2 are the times for gases 1 and 2, M1 and M2 are the molar masses, and V1 and V2 are the volumes.
