The total number of sigma bonds formed by `sp^2-sp^2` overlapping in 1, 3-butadiene is

Options

A. 5
B. 2
C. 3
D. 4

Answer

To determine the total number of sigma bonds formed by `sp^2-sp^2` overlapping in 1,3-butadiene, we need to analyze the structure of the molecule and the hybridization of its carbon atoms.

### Step-by-Step Solution:

1. **Identify the structure of 1,3-butadiene**:
1,3-butadiene is a hydrocarbon with the formula C4H6. It has a linear arrangement of four carbon atoms with alternating double bonds. The structure can be represented as:
\[ H_2C=CH-CH=CH_2 \]

2. **Determine the hybridization of carbon atoms**:
In 1,3-butadiene, the carbon atoms involved in the double bonds are sp² hybridized. Each carbon atom in the double bond forms one sigma bond with another carbon atom and one sigma bond with a hydrogen atom.

3. **Count the carbon atoms and their hybridization**:
- The four carbon atoms in 1,3-butadiene are:
- C1 (sp²)
- C2 (sp²)
- C3 (sp²)
- C4 (sp²)

4. **Identify the sigma bonds formed**:
- Each sp² carbon forms:
- 1 sigma bond with another sp² carbon.
- 1 sigma bond with a hydrogen atom.
- The double bonds consist of one sigma bond and one pi bond.

5. **Count the sigma bonds between sp² carbons**:
- C1 and C2 form one sigma bond.
- C2 and C3 form one sigma bond.
- C3 and C4 form one sigma bond.
- Therefore, there are 3 sigma bonds formed between the sp² hybridized carbon atoms.

6. **Total sigma bonds from sp²-sp² overlapping**:
The total number of sigma bonds formed by sp²-sp² overlapping in 1,3-butadiene is **3**.

### Final Answer:
The total number of sigma bonds formed by `sp^2-sp^2` overlapping in 1,3-butadiene is **3**.

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