Which of the following alkynes show acidic charater?
(i) Propyne (ii) But-1-yne (iii) But-2-yne (iv) Pent-2-yne

Explanation

To determine which of the given alkynes show acidic character, we will analyze the structure of each alkyne and identify the presence of acidic hydrogens. The acidic character in alkynes is primarily associated with the terminal alkynes, where the hydrogen atom is attached to a sp-hybridized carbon atom.

### Step-by-Step Solution:

1. **Identify the Alkynes**: The given alkynes are:
- (i) Propyne (C3H4)
- (ii) But-1-yne (C4H6)
- (iii) But-2-yne (C4H6)
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