Structural formula of ethyne is

Options

A. `H-C-=C-H`
B. `H_(3)C-C-=C-H`
C.
D.

Explanation

To derive the structural formula of ethyne, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Molecular Formula**:
- Ethyne is an alkyne with the molecular formula C₂H₂. The prefix "eth-" indicates that there are two carbon atoms.

2. **Determine the Type of Bonding**:
- The suffix "-yne" indicates that there is a triple bond between the carbon atoms. This means that each carbon atom is connected to the other by three shared electrons.

3. **Draw the Carbon Backbone**:
- Start by drawing the two carbon atoms (C) connected by a triple bond. This can be represented as:
```
C≡C
```

4. **Complete the Valency of Carbon**:
- Each carbon atom has a valency of 4. In the triple bond, each carbon shares three electrons with the other carbon, which accounts for three of their four bonds.
- Therefore, each carbon atom needs one more bond to satisfy its valency. This additional bond will be with a hydrogen atom (H).

5. **Attach Hydrogen Atoms**:
- Attach one hydrogen atom to each carbon atom to complete their valency:
```
H-C≡C-H
```

6. **Final Structural Formula**:
- The final structural formula of ethyne can be represented as:
```
H-C≡C-H
```
- This shows that each carbon is bonded to one hydrogen atom and they are connected by a triple bond.