Which of the following statement is not correct?

Question

Which term from the following is not related to adsorption?

Answer 1

The question tests the understanding of adsorption, specifically distinguishing between physical and chemical adsorption.

Let's evaluate each option:

Statement: Adsorption energy for chemical adsorption is generally greater than that of physical adsorption.
Explanation: In chemical adsorption (or chemisorption), chemical bonds are formed between the adsorbate and the surface, which typically requires significant adsorption energy. Conversely, physical adsorption is usually characterized by weaker van der Waals forces, needing considerably less energy.
Conclusion: This statement is correct.
Statement: Physical adsorption is due to van der Waals forces.
Explanation: Physical adsorption, also known as physisorption, occurs because of van der Waals forces, which are weak intermolecular forces.
Conclusion: This statement is correct.
Statement: Physical adsorption decreases at high temperature and low pressure.
Explanation: Physical adsorption is an exothermic process. According to Le Chatelier's Principle, increasing the temperature will decrease adsorption. Moreover, adsorption usually increases with an increase in pressure. Therefore, saying it decreases at high temperature is correct.
Conclusion: This statement is correct.
Statement: Physical adsorption is irreversible.
Explanation: Physical adsorption is typically reversible. This reversibility arises because it involves weak van der Waals forces, allowing the adsorbate to be easily removed from the surface.
Conclusion: This statement is incorrect, making it the correct option to the question asked.

Correct Answer: Physical adsorption is irreversible.

Answer 2

The question tests the understanding of adsorption, specifically distinguishing between physical and chemical adsorption.

Let's evaluate each option:

Statement: Adsorption energy for chemical adsorption is generally greater than that of physical adsorption.
Explanation: In chemical adsorption (or chemisorption), chemical bonds are formed between the adsorbate and the surface, which typically requires significant adsorption energy. Conversely, physical adsorption is usually characterized by weaker van der Waals forces, needing considerably less energy.
Conclusion: This statement is correct.
Statement: Physical adsorption is due to van der Waals forces.
Explanation: Physical adsorption, also known as physisorption, occurs because of van der Waals forces, which are weak intermolecular forces.
Conclusion: This statement is correct.
Statement: Physical adsorption decreases at high temperature and low pressure.
Explanation: Physical adsorption is an exothermic process. According to Le Chatelier's Principle, increasing the temperature will decrease adsorption. Moreover, adsorption usually increases with an increase in pressure. Therefore, saying it decreases at high temperature is correct.
Conclusion: This statement is correct.
Statement: Physical adsorption is irreversible.
Explanation: Physical adsorption is typically reversible. This reversibility arises because it involves weak van der Waals forces, allowing the adsorbate to be easily removed from the surface.
Conclusion: This statement is incorrect, making it the correct option to the question asked.

Correct Answer: Physical adsorption is irreversible.

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