Question

Which gas has more diffusion rate?

• A. ${\mathrm{H}}_2$
• B. ${\mathrm{N}}_2$
• C. ${\mathrm{O}}_2$

Answer 1

The correct option is A

${\mathrm{H}}_2$

Explanation for correct answer:-

Option (A) ${\mathrm{H}}_2$

• According to Graham’s law, the rate of effusion or diffusion of a gas is inversely proportional to the square root of its molar mass.
• The molar mass of hydrogen gas is 2 amu.
• Since hydrogen is the lightest gas among these gases, it will have the fastest rate of diffusion.

Explanation for incorrect answer:-

Option (B) Nitrogen:

• The molar mass of nitrogen is 14 amu.
• It is heavier than helium but lighter than oxygen hence, it will have the second-fastest rate of effusion among these gases.

Option (C) Oxygen:

• The molar mass of oxygen is 16 amu.
• It is the heaviest gas among these gases. Hence, it will have the slowest rate of diffusion.

Hence, option A is correct.