Question

Two gases, methane and oxygen are placed in two identical containers having same temperature and pressure conditions. The mass of $O_2$ gas is:

• A. negligible in comparison to the mass of methane
• B. double than the mass of methane
• C. same as the mass of methane
• D. half of the mass of methane

Answer 1

Answer: (B)

double than the mass of methane

Pressure, temperature and volume are identical for two gases. As $PV=nRT$, hence, the number of moles are also identical for the two gases.

Hence, the ratio of the masses of two gases is inversely proportional to their molar masses. The molar masses of oxygen and methane are 32 $g/mol$ and 16 $g/mol$ respectively.

Hence, the mass of oxygen gas is double the mass of methane.

Hence, the correct answer is option $\text{B}$.