Arrange the following gases in increasing rate of diffusion during the aeration process:
(A) H₂ (B) O₂ (C) Cl₂ (D) O₃ (E) Bi
Choose the correct answer:

Correct option is C

The correct answer is (3) E, C, D, B, A. The rate of diffusion of gases is inversely proportional to the square root of their molar masses (Graham's Law of Diffusion). Therefore, gases with higher molar mass diffuse more slowly than those with lower molar mass.
Step-by-Step Analysis:
1. Bi (Bismuth, e):
· Molar Mass: 208.98 g/mol (heaviest, slowest diffusion rate).
2. Cl₂ (Chlorine, c):
· Molar Mass: 70.9 g/mol.
3. O₃ (Ozone, d):
· Molar Mass: 48 g/mol.
4. O₂ (Oxygen, b):
· Molar Mass: 32 g/mol.
5. H₂ (Hydrogen, a):
· Molar Mass: 2 g/mol (lightest, fastest diffusion rate).
Hence, the correct order of increasing rate of diffusion is E (Bi), C (Cl₂), D (O₃), B (O₂), A (H₂).
Information Booster:
1. Graham's Law of Diffusion:
· States that the rate of diffusion is inversely proportional to the square root of the molar mass of the gas:

2. Applications of Diffusion:
· Important in processes such as respiration, aeration, and gas exchange in industries.
3. Heavier Gases:
· Heavier gases diffuse more slowly due to their higher molar mass.
4. Aeration Process:
· In wastewater treatment, gases like oxygen are diffused to promote microbial activity.
Additional Knowledge:
· Hydrogen (H₂):
· Lightest gas, diffuses the fastest.
· Oxygen (O₂):
· Essential for respiration and combustion processes.
· Chlorine (Cl₂):
· Heavier gas, used for disinfection and industrial applications.
· Ozone (O₃):
· Used for sterilization and environmental protection.
· Bismuth (Bi):
· A heavy element that generally exists in solid form but is theoretically included for diffusion comparison purposes.