Percentage of nitric acid obtained in Ostwald's process is

Options

A. `61%`
B. `68%`
C. `74%`
D. `82%`

Answer

To determine the percentage of nitric acid obtained in the Ostwald process, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Ostwald Process**:
The Ostwald process is a method for producing nitric acid (HNO3) from ammonia (NH3) through catalytic oxidation. It involves three main steps.

2. **Step 1: Catalytic Oxidation of Ammonia**:
- The reaction involves 4 molecules of ammonia (NH3) reacting with 5 molecules of oxygen (O2) in the presence of a catalyst at high temperature (around 500 K).
- The reaction can be represented as:
\[ 4 \text{NH}_3(g) + 5 \text{O}_2(g) \rightarrow 4 \text{NO}(g) + 6 \text{H}_2O(g) \]
- Here, nitric oxide (NO) and water (H2O) are produced.

3. **Step 2: Oxidation of Nitric Oxide**:
- The nitric oxide produced is then oxidized further:
\[ 2 \text{NO}(g) + \text{O}_2(g) \rightleftharpoons 2 \text{NO}_2(g) \]
- This step converts nitric oxide to nitrogen dioxide (NO2).

4. **Step 3: Absorption of Nitrogen Dioxide in Water**:
- The nitrogen dioxide is then absorbed in water to form nitric acid:
\[ 3 \text{NO}_2(g) + \text{H}_2O(l) \rightarrow 2 \text{HNO}_3(aq) + \text{NO}(g) \]
- This step yields nitric acid and some unreacted nitric oxide.

5. **Concentration of Nitric Acid**:
- The nitric acid produced can be concentrated through distillation.
- The maximum concentration achievable through this process is approximately 68%.

6. **Conclusion**:
- Therefore, the percentage of nitric acid obtained in the Ostwald process is **68%**.

### Final Answer:
The percentage of nitric acid obtained in the Ostwald process is **68%**.

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