Extent of adsorption of adsorbate from solution phase increases with:

Options

A. increase in amount of adsorbate in solution.
B. decrease in surface area of adsorbent.
C. increase in temperature of solution.
D. decrease in amount of adsorbate in solution.

Explanation

To determine the factors that influence the extent of adsorption of an adsorbate from a solution phase, we need to analyze the options provided and understand the principles of adsorption.

### Step-by-Step Solution:

1. **Understanding Adsorption**:
- Adsorption is the process where molecules of a substance (adsorbate) adhere to the surface of another substance (adsorbent).
- The extent of adsorption refers to how much of the adsorbate is collected on the surface of the adsorbent.

2. **Analyzing the Options**:
- **Option 1: Increase in amount of adsorbate in solution**:
- When the concentration of the adsorbate in the solution increases, more molecules are available to interact with the surface of the adsorbent. This leads to an increase in the extent of adsorption.
- **Conclusion**: This option is correct.

- **Option 2: Decrease in surface area**:
- The surface area of the adsorbent is crucial for adsorption. A smaller surface area means fewer sites for the adsorbate to adhere to, which would decrease the extent of adsorption.
- **Conclusion**: This option is incorrect.

- **Option 3: Increase in temperature of solution**:
- Generally, adsorption is an exothermic process. Increasing the temperature can lead to a decrease in the extent of adsorption because higher temperatures provide more energy to the adsorbate molecules, making them less likely to adhere to the surface.
- **Conclusion**: This option is incorrect.

- **Option 4: Decrease in amount of adsorbate in solution**:
- Reducing the concentration of the adsorbate means fewer molecules are available to interact with the adsorbent, which would lead to a decrease in the extent of adsorption.
- **Conclusion**: This option is incorrect.

3. **Final Answer**:
- The extent of adsorption of adsorbate from solution phase increases with the **increase in amount of adsorbate in solution**. Therefore, the correct answer is **Option 1**.