Complete the following using the correct word given in the brackets.
Nitric acid is manufactured by Ostwald process on catalytic oxidation of ____

Explanation

To complete the statement, we need to identify the substance that is oxidized in the Ostwald process for the manufacture of nitric acid (HNO3).

### Step-by-Step Solution:

1. **Identify the Process**: The Ostwald process is a well-known method for producing nitric acid. It involves the catalytic oxidation of ammonia (NH3).

2. **Understanding Catalytic Oxidation**: In the Ostwald process, ammonia is oxidized in the presence of oxygen (O2) using a catalyst, typically vanadium pentoxide (V2O5).

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