Given van der Waals constant for `NH_(3), H_(2), O_(2) and CO_(2)` are respectively `4.17, 0.244, 1.36 and 3.59`, which one of the following gases is most easily liquefied?

Options

A. `NH_(3)`
B. `H_(2)`
C. `O_(2)`
D. `CO_(2)`

Explanation

To determine which gas among NH₃, H₂, O₂, and CO₂ is most easily liquefied, we can analyze the van der Waals constants provided. The van der Waals equation accounts for the volume occupied by gas molecules and the intermolecular forces between them. The constant 'a' in the van der Waals equation is a measure of the attractive forces between particles; a higher value indicates stronger intermolecular forces, which generally leads to easier liquefaction.

### Step-by-Step Solution:

1. **Identify the van der Waals constants**:
- For NH₃ (Ammonia): a = 4.17
- For H₂ (Hydrogen): a = 0.244
- For O₂ (Oxygen): a = 1.36
- For CO₂ (Carbon Dioxide): a = 3.59

2. **Compare the values of 'a'**:
- The values of 'a' for the gases are:
- NH₃: 4.17
- H₂: 0.244
- O₂: 1.36
- CO₂: 3.59

3. **Determine which gas has the highest 'a' value**:
- Among the given gases, NH₃ has the highest 'a' value of 4.17.

4. **Conclusion**:
- Since NH₃ has the highest van der Waals constant (a = 4.17), it indicates that NH₃ has the strongest intermolecular forces among the gases listed. Therefore, NH₃ is the gas that is most easily liquefied.

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