Maximum deviation from ideal gas is expected from

Options

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

Explanation

To solve the question "Maximum deviation from ideal gas is expected from," we will analyze the behavior of the given gases in relation to ideal gas behavior, focusing on the van der Waals constants (a and b) and the presence of intermolecular forces.

### Step-by-Step Solution:

1. **Understanding Ideal Gas Behavior**:
- Ideal gases follow the ideal gas law (PV = nRT) perfectly under all conditions. However, real gases deviate from this behavior due to intermolecular forces and the volume occupied by gas particles.

2. **Identifying Van der Waals Constants**:
- The van der Waals equation accounts for the deviations of real gases from ideal behavior. The constants 'a' and 'b' in the van der Waals equation represent:
- 'a': the attraction between particles (intermolecular forces).
- 'b': the volume occupied by the gas particles.

3. **Evaluating the Given Gases**:
- The gases provided are H2, N2, CH4, and NH3.
- We need to determine which gas has the highest van der Waals constants 'a' and 'b', indicating stronger intermolecular forces and greater deviation from ideal gas behavior.

4. **Analyzing Each Gas**:
- **H2 (Hydrogen)**: A diatomic molecule with weak intermolecular forces (London dispersion forces). Low 'a' and 'b' values.
- **N2 (Nitrogen)**: Another diatomic molecule with similar weak forces as H2. Low 'a' and 'b' values.
- **CH4 (Methane)**: A non-polar molecule with weak London dispersion forces. Also has low 'a' and 'b' values.
- **NH3 (Ammonia)**: A polar molecule capable of hydrogen bonding, leading to strong intermolecular forces. This results in higher 'a' and 'b' values.

5. **Conclusion**:
- Among the gases, NH3 has the strongest intermolecular forces due to hydrogen bonding, leading to the highest values of 'a' and 'b'. Therefore, NH3 will show the maximum deviation from ideal gas behavior.

### Final Answer:
The maximum deviation from ideal gas is expected from **NH3 (Ammonia)**.