The number of sigma `(sigma)` and pi `(pi)` bonds present in acetylene are _____ respectively.

Options

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

Explanation

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

### Step 1: Understand the Structure of Acetylene
Acetylene is a simple alkyne with the molecular formula C₂H₂. It consists of two carbon atoms and two hydrogen atoms.

### Step 2: Draw the Lewis Structure
The Lewis structure of acetylene can be represented as follows:
```
H - C ≡ C - H
```
In this structure, the two carbon atoms are connected by a triple bond, and each carbon atom is also bonded to one hydrogen atom.

### Step 3: Identify the Types of Bonds
1. **C-H Bonds**: Each carbon atom forms a single bond with a hydrogen atom. Each of these bonds is a sigma bond.
2. **C≡C Bond**: The triple bond between the two carbon atoms consists of:
- 1 sigma bond
- 2 pi bonds

### Step 4: Count the Sigma Bonds
- There are 2 C-H sigma bonds (one for each hydrogen).
- There is 1 C-C sigma bond (the single bond in the triple bond).

Total sigma bonds = 2 (C-H) + 1 (C-C) = **3 sigma bonds**.

### Step 5: Count the Pi Bonds
- The C≡C triple bond has 2 pi bonds.

Total pi bonds = 2 (from the C≡C bond) = **2 pi bonds**.

### Conclusion
Thus, in acetylene (C₂H₂), there are **3 sigma bonds** and **2 pi bonds**.

### Final Answer
The number of sigma and pi bonds present in acetylene are **3 and 2**, respectively.

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