The phenomenon of simultaneous absorption and adsorption is called - 

Options

A. Sorption
B. Desorption
C. Chemisorption
D. Absorption

Answer

To solve the question, "The phenomenon of simultaneous absorption and adsorption is called -", we need to analyze the terms involved and find the correct answer from the provided options.

### Step-by-Step Solution:

1. **Understanding Absorption and Adsorption**:
- **Absorption** refers to the process where a substance is taken up by the entire volume of another substance. For example, when a liquid is absorbed by a sponge, it penetrates the sponge's material.
- **Adsorption**, on the other hand, is the process where molecules adhere to the surface of a solid or liquid. For instance, when dye sticks to the surface of a fabric, it is an example of adsorption.

2. **Identifying the Key Terms**:
- The question asks for a term that describes the simultaneous occurrence of both absorption and adsorption.
- The options provided are: sorption, desorption, chemo sorption, and absorption.

3. **Analyzing the Options**:
- **Sorption**: This term is often used to describe the combined process of absorption and adsorption. Therefore, it fits the description of simultaneous absorption and adsorption.
- **Desorption**: This is the reverse process of adsorption, where molecules are released from a surface. This does not fit the question.
- **Chemo Sorption**: This refers to the process involving chemical bonding between the adsorbate and the adsorbent. While it involves adsorption, it does not encompass absorption.
- **Absorption**: This is already mentioned in the question and cannot be the answer.

4. **Conclusion**:
- The correct answer is **sorption**, as it encompasses both absorption and adsorption occurring simultaneously.

### Final Answer:
The phenomenon of simultaneous absorption and adsorption is called **sorption**.

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