Mercurous chloride turns black on adding `NH_(4)OH` to it. Explain.

Explanation

To explain why mercurous chloride turns black upon the addition of ammonium hydroxide (NH₄OH), we can break down the process into a series of steps:

### Step 1: Identify Mercurous Chloride
Mercurous chloride is represented by the chemical formula Hg₂Cl₂. It is important to recognize that this compound contains two mercury (Hg) atoms and two chloride (Cl) ions.

### Step 2: Reaction with Ammonium Hydroxide
When mercurous chloride (Hg₂Cl₂) is treated with ammonium hydroxide (NH₄OH), it undergoes a chemical reaction. Ammonium hydroxide can also be represented as ammonia (NH₃) in aqueous solution.

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