Chemisortion is………………… while physical adsorption adsorption is ………………….. In nature.

Answer

**Step-by-Step Solution:**

1. **Definition of Chemisorption:**
- Chemisorption refers to the process where an adsorbate forms a strong chemical bond with the adsorbent. This bond is typically a covalent or ionic bond, which involves the sharing or transfer of electrons between the adsorbate and adsorbent.

2. **Nature of Chemisorption:**
- Due to the formation of strong chemical bonds, chemisorption is generally considered irreversible. Once the adsorbate is bonded to the adsorbent, it cannot be easily removed without breaking the chemical bond, which often alters the adsorbate.

3. **Definition of Physical Adsorption (Physisorption):**
- Physical adsorption, or physisorption, involves the adhesion of molecules to a surface through weak intermolecular forces, primarily van der Waals forces. These forces are much weaker than the chemical bonds formed in chemisorption.

4. **Nature of Physical Adsorption:**
- Physisorption is reversible in nature. The weak van der Waals forces can be easily overcome by applying heat or reducing pressure, allowing the adsorbate to be released from the adsorbent without any significant alteration to their chemical structure.

5. **Conclusion:**
- Therefore, chemisorption is irreversible due to the strong chemical bonds formed, while physical adsorption is reversible due to the weak van der Waals forces involved.

**Final Answer:**
Chemisorption is irreversible while physical adsorption is reversible in nature.

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