Hydrogen is used in the manufacturing of ................... which is used to prepare fertilisers.

Answer

**Step-by-Step Solution:**

1. **Identify the Role of Hydrogen:**
Hydrogen is a key element in various chemical processes, including the production of fertilizers.

2. **Understand Fertilizers:**
Fertilizers are substances that are added to soil to enhance its fertility and promote plant growth.

3. **Identify the Specific Fertilizer:**
One of the primary fertilizers produced using hydrogen is ammonia, which is chemically represented as NH₃.

4. **Explain the Production of Ammonia:**
Ammonia is produced by combining hydrogen (H₂) with nitrogen (N₂) from the atmosphere. This process is typically done through the Haber process.

5. **Conclusion:**
Therefore, hydrogen is used in the manufacturing of ammonia, which is a crucial component in the preparation of fertilizers.

**Final Answer:**
Hydrogen is used in the manufacturing of **ammonia**, which is used to prepare fertilizers.

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