Nitric acid is manufactured by

Options

A. Catalytic oxidation of ammonia
B. Nitration of hydrogen and oxygen
C. Contact process
D. Haber process

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the manufacturing process of nitric acid. We need to identify the correct method from the given options.

2. **Identifying the Options**:
- A) Catalytic oxidation of ammonia (Ostwald process)
- B) Nitration of hydrogen and oxygen
- C) Contact process
- D) Haber’s process

3. **Analyzing Option A (Catalytic Oxidation of Ammonia)**:
- This process is known as the Ostwald process.
- It involves the oxidation of ammonia (NH₃) in the presence of oxygen (O₂) to produce nitric oxide (NO).
- The reaction can be represented as:
\[ 4NH_3 + 5O_2 \rightarrow 4NO + 6H_2O + \text{heat} \]
- This reaction occurs at a high temperature (around 600°C) and uses catalysts such as platinum, copper, or nickel.

4. **Secondary Oxidation**:
- The nitric oxide produced is then further oxidized to nitrogen dioxide (NO₂):
\[ 2NO + O_2 \rightarrow 2NO_2 \]
- This step occurs at a lower temperature (around 150°C) and is crucial for the next stage.

5. **Absorption of Nitrogen Dioxide**:
- The nitrogen dioxide gas is then absorbed in water to form nitric acid (HNO₃):
\[ 3NO_2 + H_2O \rightarrow 2HNO_3 + NO \]
- This step occurs in a special absorption tower where the NO₂ gas is dissolved in water.

6. **Conclusion**:
- Based on the analysis, we conclude that nitric acid is manufactured by the catalytic oxidation of ammonia, which is the Ostwald process. Therefore, the correct answer is **Option A**.

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