The value of van der Waals constant `a` for the gases `O_(2)`, `N_(2)`, `NH_(3)`, and `CH_(4)` are `1.360`, `1.390`, `4.170`, and `2.253 L^(2) atm mol^(-2)`, respectively. The gas which can most easily be liquefied is

Options

A. `O_(2)`
B. `N_(2)`
C. `NH_(3)`
D. `CH_(4)`.

Explanation

To determine which gas can be most easily liquefied among O₂, N₂, NH₃, and CH₄ based on their van der Waals constant `a`, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the van der Waals constant `a`:**
The van der Waals constant `a` is a measure of the attractive forces between gas molecules. A higher value of `a` indicates stronger intermolecular attractions, which makes it easier for the gas to be liquefied.

2. **List the values of `a` for the given gases:**
- O₂: `1.360 L² atm mol⁻²`
- N₂: `1.390 L² atm mol⁻²`
- NH₃: `4.170 L² atm mol⁻²`
- CH₄: `2.253 L² atm mol⁻²`

3. **Compare the values of `a`:**
We can see that:
- O₂ has `a = 1.360`
- N₂ has `a = 1.390`
- NH₃ has `a = 4.170`
- CH₄ has `a = 2.253`

4. **Identify the gas with the highest `a` value:**
Among the listed values, NH₃ has the highest value of `a` (4.170). This indicates that NH₃ has the strongest intermolecular attractions compared to the other gases.

5. **Conclusion:**
Since NH₃ has the highest van der Waals constant `a`, it can be concluded that NH₃ is the gas that can most easily be liquefied.

### Final Answer:
The gas which can most easily be liquefied is **NH₃ (Ammonia)**.

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