Total number of sigma and `pi` bonds present in ethyne are

Options

A. 4 and 3 respectively
B. 3 and 2 respectively
C. 2 and 3 respectively
D. 1 and 2 respectively

Answer

To determine the total number of sigma (σ) and pi (π) bonds present in ethyne (C₂H₂), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Structure of Ethyne**:
Ethyne, also known as acetylene, has the molecular formula C₂H₂. The structure can be represented as:
```
H-C≡C-H
```
This indicates that there is a triple bond between the two carbon atoms.

2. **Identify the Types of Bonds**:
In the triple bond (C≡C), there are:
- 1 sigma bond
- 2 pi bonds

3. **Count the Sigma Bonds**:
In addition to the triple bond between the two carbon atoms, each carbon atom is also bonded to one hydrogen atom. Therefore:
- Each C-H bond is a sigma bond.
- There are 2 C-H bonds (one for each carbon).

So, the total number of sigma bonds is:
- 1 (from C≡C) + 2 (from C-H) = 3 sigma bonds.

4. **Count the Pi Bonds**:
As established earlier, the triple bond consists of 2 pi bonds. Thus, the total number of pi bonds is:
- 2 pi bonds (from C≡C).

5. **Summarize the Total Bonds**:
- Total Sigma Bonds = 3
- Total Pi Bonds = 2

### Final Answer:
The total number of sigma and pi bonds present in ethyne is:
- Sigma bonds: 3
- Pi bonds: 2