Question

Which gas will diffuse the fastest under identical conditions of temperature and pressure?

• A. Oxygen (O₂)
• B. Nitrogen (N₂)
• C. Ammonia (NH₃)
• D. Hydrogen (H₂)

Answer 1

The Correct Option is D

To determine which gas will diffuse the fastest under identical conditions of temperature and pressure, we can use Graham's law of effusion. This law states that the rate of effusion of a gas is inversely proportional to the square root of its molar mass (M). Mathematically, it can be expressed as:

Rate of effusion ∝ 1/√M

Let's compare the molar masses of the given gases:

• Oxygen (O₂): Molar mass = 32 g/mol
• Nitrogen (N₂): Molar mass = 28 g/mol
• Ammonia (NH₃): Molar mass = 17 g/mol
• Hydrogen (H₂): Molar mass = 2 g/mol

Since hydrogen (H₂) has the smallest molar mass among the given options, according to Graham's law, it will diffuse the fastest.

Therefore, the correct answer is Hydrogen (H₂).