The values of the van der Waals' constant a for some gases are given below.
`H_2 = 0.245 " atm " L^2 mol^(-2)`
`O_2 = 1.360 " atm " L^2 mol^(-2)`
`CO_2 = 3.590 " atm " L^2 mol^(-2)`
`NH_3 = 4.170 " atm " L^2 mol^(-2)`
Arrange these gases in the decreasing order of their liquefaction tendencies.

Explanation

To arrange the gases in decreasing order of their liquefaction tendencies based on the given values of the van der Waals constant \( a \), we can follow these steps:

### Step 1: Understand the significance of the van der Waals constant \( a \)
The van der Waals constant \( a \) measures the magnitude of the intermolecular attractive forces within a gas. A higher value of \( a \) indicates stronger intermolecular attractions, which generally leads to a greater tendency for the gas to liquefy.

### Step 2: List the given values of \( a \) for each gas
- \( H_2: 0.245 \, \text{atm} \, \text{L}^2 \, \text{mol}^{-2} \)
- \( O_2: 1.360 \, \text{atm} \, \text{L}^2 \, \text{mol}^{-2} \)
...