Mo is used in the manufacture of

Options

A. `NH_3`
B. `HNO_2`
C. `HNO_3`
D. `HCl`

Explanation

To solve the question regarding the use of molybdenum (Mo) in manufacturing, we can follow these steps:

### Step 1: Identify the Processes Involved
Molybdenum is known to be used in various chemical processes. We need to focus on the options provided: NH3 (ammonia), HNO2 (nitrous acid), HNO3 (nitric acid), and HCl (hydrochloric acid).

**Hint:** Think about the common industrial processes where these compounds are produced.

### Step 2: Analyze the Haber Process
The Haber process is a well-known method for synthesizing ammonia (NH3) from nitrogen (N2) and hydrogen (H2) gases. This process requires a catalyst to facilitate the reaction.

**Hint:** Recall that the Haber process is specifically associated with ammonia production.

### Step 3: Role of Molybdenum
In the Haber process, iron is typically used as the catalyst. However, molybdenum is not the primary catalyst; instead, it acts as a promoter. This means that molybdenum enhances the effectiveness of the iron catalyst, leading to a higher yield of ammonia.

**Hint:** Consider how promoters function in catalytic reactions and their importance in increasing efficiency.

### Step 4: Conclusion
Given that molybdenum is used to enhance the efficiency of the iron catalyst in the Haber process, we can conclude that molybdenum is used in the manufacture of ammonia (NH3).

**Final Answer:** Molybdenum (Mo) is used in the manufacture of NH3 (ammonia).

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