If the solubility of the given gases in water decreases in the order of formaldehyde, methane, vinyl chloride, argon.

Match List-I with List-II.

Choose the correct answer from the options given below:

(A)-(III), (B)-(IV), (C)-(I), (D)-(II)

The correct answer is Option (4) → A)-(III), (B)-(IV), (C)-(I), (D)-(II)

Lower Solubility Higher $K_{H}$ (Henry's Law Constant)

The problem states: Solubility decreases in the order: Formaldehyde > Methane > Vinyl chloride > Argon.

Therefore, the $K_{H}$ values should increase in the same order.

Order of increasing $K_{H}$ values: Formaldehyde < Methane < Vinyl chloride < Argon

Given $K_{H}$ values (in increasing order):

1. $1.83\times10^{-5}$ (Smallest $K_{H}$, so Highest Solubility)

2. 0.413 

3. 0.611

4. 40.3 (Largest $K_H$, so Lowest Solubility)