Question

Which of the following will have the slowest rate of diffusion at a given temperature?

Answer 1

Answer:

Chlorine gas (Cl₂)

Explanation:

• According to the Graham's law of diffusion, the diffusion rate of a gas is inversely proportional to the square root of its density or molar mass.
• Therefore, a lighter gas will diffuse faster at a given temperature compared to a heavy gas.
• Consequently, the heavier a gas is then the denser it is and the slower it diffuses at a given temperature and vice versa.

In this case we are given gases, CI₂

, H₂,He and Ne.

• We are required to identify the gas that will diffuse at the slowest rate.
• In other words we are required to determine the heaviest gas.

Looking at the molar mass of the gases given;

Cl₂- 70.91 g/mol

H₂- 2.02 g/mol

He - 4.00 g/mol

Ne- 20.18 g/mol

Therefore, chlorine gas is the heaviest and thus will diffuse at the slowest rate among the choices given.