The second homologue of alkyne is

Options

A. CH
B. `C_2H_2`
C. `C_2H_4`
D. `C_3 H_4`

Explanation

To find the second homologue of alkyne, we need to understand the structure of alkynes and how they are classified.

### Step-by-Step Solution:

1. **Understand Alkynes**: Alkynes are hydrocarbons that contain at least one carbon-carbon triple bond. The general formula for alkynes is CnH2n-2, where 'n' is the number of carbon atoms.

2. **Identify the First Homologue**: The first member (or homologue) of the alkyne series is ethyne (C2H2), which has two carbon atoms and one triple bond.

3. **Determine the Second Homologue**: To find the second homologue, we increase the number of carbon atoms by one. Thus, the second member will have three carbon atoms.

4. **Write the Formula for the Second Homologue**: Using the general formula for alkynes (CnH2n-2), if we substitute n = 3 (for the second homologue), we get:
- C3H(2*3-2) = C3H4

5. **Name the Second Homologue**: The compound with three carbon atoms and a triple bond is called propyne (C3H4).

### Final Answer:
The second homologue of alkyne is **propyne (C3H4)**.

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