Benzaldehyde when treated with an alcoholic solution of ______ forms ______ .

Explanation

To solve the question, we need to identify the reagent that benzaldehyde reacts with in an alcoholic solution to form a specific product. The process involved is known as benzoin condensation.

### Step-by-Step Solution:

1. **Identify the Reactant**: The reactant given is benzaldehyde, which has the chemical formula C₇H₆O or C₆H₅CHO.

2. **Identify the Reagent**: The question specifies that benzaldehyde is treated with an alcoholic solution. The common reagent used in this reaction is potassium cyanide (KCN).

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