Question

Which of the following general reactions is an example for heterogeneous catalysis?

• A. \( A_2 (g) + B_2 (g) \xrightarrow{C (g)} 2AB (g) \)
• B. \( A (s) + B (s) \xrightarrow{C (s)} D (s) \)
• C. \( A (g) + B (g) \xrightarrow{C (s)} D (g) \)
• D. \( A_2 (g) + B_2 (g) \xrightarrow{C (g)} D (s) \)

Hint:

- Heterogeneous catalysts exist in a different phase than the reactants (e.g., solid catalysts for gas-phase reactions). - Common examples include catalytic converters in cars (solid platinum catalyzing gas reactions).

Answer 1

The Correct Option is C

Step 1: Understanding Heterogeneous Catalysis
- Heterogeneous catalysis occurs when the reactants and catalyst exist in different phases (e.g., solid catalyst with gaseous reactants).
- In contrast, homogeneous catalysis occurs when the catalyst and reactants are in the same phase.
Step 2: Identifying the Correct Option
- (A) Involves only gases, so it is homogeneous catalysis.
- (B) Involves only solids, not catalysis.
- (C) The reactants are gases, and the catalyst is solid (\( C (s) \)), which is a classic example of heterogeneous catalysis.
- (D) The catalyst and reactants are in the same phase (gaseous), making it homogeneous. 
Final Answer: The correct example of heterogeneous catalysis is option (C).