The catalyst used in the manufacture of sulphuric acid by contact process is `:

Options

A. `Al_(2)O_(3)`
B. `Cr_(2)O_(3)`
C. `V_(2)O_(5)`
D. `MnO_(2)`

Answer

To determine the catalyst used in the manufacture of sulfuric acid by the contact process, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Contact Process**:
- The contact process is the method used to produce sulfuric acid (H₂SO₄) in large quantities. It involves the oxidation of sulfur dioxide (SO₂) to sulfur trioxide (SO₃) using oxygen (O₂) in the presence of a catalyst.

2. **Identifying the Catalyst**:
- Historically, platinum was used as a catalyst in this process. However, due to its high cost and susceptibility to impurities (like arsenic) in the feedstock, it is no longer favored.

3. **Current Preferred Catalyst**:
- The current preferred catalyst for the contact process is vanadium(V) oxide, represented as V₂O₅. This catalyst is more effective and resistant to impurities compared to platinum.

4. **Chemical Reaction**:
- The overall reaction in the contact process can be represented as:
\[ 2 \text{SO}_2(g) + \text{O}_2(g) \xrightarrow{\text{V}_2\text{O}_5} 2 \text{SO}_3(g) \]
- This equation shows that sulfur dioxide reacts with oxygen in the presence of vanadium(V) oxide to produce sulfur trioxide.

5. **Conclusion**:
- Therefore, the catalyst used in the manufacture of sulfuric acid by the contact process is vanadium(V) oxide (V₂O₅).

### Final Answer:
The catalyst used in the manufacture of sulfuric acid by the contact process is **vanadium(V) oxide (V₂O₅)**.

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