A mixture of ammonia and air at about `800^@` C in the presence of Pt gauze forms

Options

A. `N_2 O`
B. `NO`
C. `NH_2 OH`
D. `N_2 O_3`

Explanation

To solve the question regarding the reaction of a mixture of ammonia and air at about 800°C in the presence of platinum gauze, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**: The reactants in this scenario are ammonia (NH₃) and oxygen (O₂) from the air.

2. **Understand the Conditions**: The reaction takes place at a high temperature of about 800°C and in the presence of platinum gauze, which acts as a catalyst.

3. **Write the Reaction**: The reaction between ammonia and oxygen can be represented as follows:
\[ 4 \text{NH}_3 + 5 \text{O}_2 \rightarrow 4 \text{NO} + 6 \text{H}_2 \]

4. **Balance the Reaction**: Ensure that the number of atoms of each element is balanced on both sides of the equation. In this case, the equation is already balanced.

5. **Identify the Product**: From the balanced equation, we can see that one of the products formed is nitric oxide (NO).

6. **Conclusion**: Therefore, when a mixture of ammonia and air reacts at 800°C in the presence of platinum gauze, the primary product formed is nitric oxide (NO).

### Final Answer:
The reaction produces nitric oxide (NO).

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