What is meant by the following terms ? Give an example of the reaction in the case.
i. Cyanohydrin ii. Acetal
iii. Semicarbazone

Explanation

To answer the question regarding the terms cyanohydrin, acetal, and semicarbazone, we will define each term and provide an example of the reaction that produces each compound.

### Step 1: Define Cyanohydrin
**Cyanohydrin** is a compound that contains a hydroxyl group (-OH) and a cyano group (-CN) attached to the same carbon atom. This carbon atom is typically derived from a carbonyl compound (aldehyde or ketone).

**Example Reaction:**
Cyanohydrin can be formed by the reaction of a carbonyl compound (like an aldehyde or ketone) with hydrogen cyanide (HCN) in the presence of a base (OH-).

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