Which of the following gases, will be adsorbed maximum on a solid surface `:`

Options

A. `CO_(2)`
B. `O_(2)`
C. `N_(2)` is added at constant volume
D. `H_(2)`

Explanation

To determine which gas will be adsorbed the most on a solid surface, we need to consider the concept of adsorption and its relationship with the critical temperature of the gases.

### Step-by-Step Solution:

1. **Understanding Adsorption**: Adsorption is the process where gas molecules adhere to the surface of a solid. The extent of adsorption depends on several factors, including the nature of the gas and the solid surface, as well as the temperature.

2. **Critical Temperature**: The critical temperature of a gas is the temperature above which it cannot be liquefied, regardless of the pressure applied. Gases with higher critical temperatures are generally more easily liquefied and have stronger intermolecular forces.

3. **List of Gases**: The gases given in the question are:
- CO2 (Carbon Dioxide)
- O2 (Oxygen)
- N2 (Nitrogen)
- H2 (Hydrogen)

4. **Comparing Critical Temperatures**:
- **CO2**: Has a relatively high critical temperature (31.0 °C).
- **O2**: Has a critical temperature of about -118.6 °C.
- **N2**: Has a critical temperature of about -146.9 °C.
- **H2**: Has a critical temperature of about -240 °C.

5. **Analysis**: Among these gases, CO2 has the highest critical temperature. This indicates that CO2 can be liquefied at a higher temperature compared to the others, which suggests that it has stronger intermolecular forces.

6. **Conclusion**: Since the adsorption of a gas on a solid surface is directly proportional to its critical temperature, CO2 will be adsorbed the most on a solid surface compared to O2, N2, and H2.

### Final Answer:
The gas that will be adsorbed maximum on a solid surface is **CO2** (Option 1).

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