Which of the following is an incorrect statement?

Options

A. Most heterogeneous catalytic reactions involve the solid surface of the catalyst
B. Heterogeneous catalyst primarily function by lowering the activation energy of the reaction
C. A solid catalyst present in the power form is more effective as it has large surface area
D. The catalyst may be deactivated by heating it to a high temperature in vacuum

Answer

To determine which of the statements regarding heterogeneous catalysis is incorrect, let's analyze each statement one by one.

### Step 1: Analyze Statement 1
**Statement 1:** Most heterogeneous catalytic reactions involve the solid surface of the catalyst.
- **Analysis:** This statement is correct. Heterogeneous catalysis typically involves a solid catalyst that provides a surface for the reactants to adsorb and react.

### Step 2: Analyze Statement 2
**Statement 2:** Heterogeneous catalysts primarily function by lowering the activation energy of the reaction.
- **Analysis:** This statement is also correct. Heterogeneous catalysts work by providing an alternative reaction pathway with a lower activation energy, which increases the reaction rate.

### Step 3: Analyze Statement 3
**Statement 3:** A solid catalyst present in powdered form is more effective as it has a large surface area.
- **Analysis:** This statement is correct as well. A powdered catalyst has a greater surface area compared to larger pieces, allowing more reactant molecules to adsorb and react, thus enhancing catalytic activity.

### Step 4: Analyze Statement 4
**Statement 4:** The catalyst may get deactivated by heating to a higher temperature in vacuum.
- **Analysis:** This statement is incorrect. While catalysts can be deactivated by various means (such as poisoning or thermal degradation), heating in a vacuum does not inherently lead to deactivation. In fact, heating can sometimes regenerate a catalyst by removing adsorbed impurities.

### Conclusion
Based on the analysis, the incorrect statement is **Statement 4**: "The catalyst may get deactivated by heating to a higher temperature in vacuum."

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