Question

Which of the following catalysts is used in the manufacture of NH$_3$ by Haber’s process?

• A. Finely divided iron
• B. Finely divided molybdenum
• C. Finely divided nickel
• D. Finely divided platinum

Hint:

In Haber’s process: Catalyst = Finely divided iron, Promoter = Molybdenum.

Answer 1

The Correct Option is A

Step 1: Recall Haber’s process.
Ammonia is manufactured by Haber’s process: \[ N_2 + 3H_2 \leftrightharpoons 2NH_3 \quad (\Delta H = -92\,kJ) \] Step 2: Catalyst used.
The catalyst used is finely divided iron with molybdenum as a promoter.
Step 3: Analyze options.
- Iron: Correct main catalyst.
- Molybdenum: Used only as promoter, not the main catalyst.
- Nickel: Used in hydrogenation, not Haber’s process.
- Platinum: Expensive and not used here.
Step 4: Conclusion.
Thus, the correct answer is (A) Finely divided iron.