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`

Answer

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

### Step 1: Understand the van der Waals constant \( a \)
The van der Waals constant \( a \) indicates the strength of intermolecular forces in a gas. A higher value of \( a \) means stronger intermolecular attractions, which facilitates the liquefaction of the gas.

### Step 2: List the given values of \( a \)
- For O₂: \( a = 1.360 \, \text{L}^2 \, \text{atm} \, \text{mol}^{-2} \)
- For N₂: \( a = 1.390 \, \text{L}^2 \, \text{atm} \, \text{mol}^{-2} \)
- For NH₃: \( a = 4.170 \, \text{L}^2 \, \text{atm} \, \text{mol}^{-2} \)
- For CH₄: \( a = 2.253 \, \text{L}^2 \, \text{atm} \, \text{mol}^{-2} \)

### Step 3: Compare the values of \( a \)
Now, we compare the values of \( a \) for each gas:
- O₂: 1.360
- N₂: 1.390
- NH₃: 4.170
- CH₄: 2.253

### Step 4: Identify the highest value
Among the values listed, the highest value of \( a \) is for NH₃, which is 4.170.

### Step 5: Conclusion
Since NH₃ has the highest van der Waals constant \( a \), it indicates that NH₃ has the strongest intermolecular forces among the given gases. Therefore, NH₃ can be liquefied most easily compared to O₂, N₂, and CH₄.

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

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