The conversion of primary aromatic amines into diazonium salts is known as

Explanation

**Step-by-Step Solution:**

1. **Understanding the Reaction**: The conversion of primary aromatic amines into diazonium salts is a specific type of chemical reaction. This process is essential in organic chemistry, particularly in the synthesis of various aromatic compounds.

2. **Identifying the Reaction Name**: The reaction where primary aromatic amines are converted into diazonium salts is known as the **diazotization reaction**.

3. **Reactants Involved**: In this reaction, a primary aromatic amine is reacted with sodium nitrite (NaNO2) in the presence of a mild acid, commonly hydrochloric acid (HCl).

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