Ethyne undergoes addition reaction. State one reason.

Explanation

**Step-by-Step Text Solution:**

1. **Understanding Ethyne**: Ethyne, also known as acetylene, is a hydrocarbon with the chemical formula C₂H₂. It contains a triple bond between the two carbon atoms.

2. **Definition of Addition Reaction**: An addition reaction is a type of chemical reaction where two or more molecules combine to form a larger molecule. In the case of alkenes and alkynes, this typically involves the addition of atoms across the double or triple bonds.

3. **Presence of Active Sites**: The triple bond in ethyne (C≡C) is considered an "active site" because it is a region of high electron density. This makes it susceptible to reactions with other molecules, allowing for the addition of new atoms or groups.

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