Question

Number of sigma and pi bonds in methyl but-1-ene is:

• A. 10 sigma bonds and 3 pi bonds
• B. 9 sigma bonds and 4 pi bonds
• C. 8 sigma bonds and 4 pi bonds
• D. 8 sigma bonds and 3 pi bonds

Hint:

In a double bond, one bond is sigma and the other is pi. When counting bonds, remember that single bonds are always sigma and double bonds consist of one sigma and one pi bond.

Answer 1

The Correct Option is A

Methyl but-1-ene has the structure \( \text{CH}_3-\text{CH}_2-\text{C}=\text{CH}_2 \), where: - The single bonds are sigma bonds, - The double bonds consist of one sigma bond and one pi bond.

1. Step 1: Count the sigma bonds: - Each single bond in the molecule is a sigma bond. The structure consists of 10 single bonds: - 3 C-H bonds in the methyl group (\( \text{CH}_3 \)), - 2 C-H bonds in the ethyl group (\( \text{CH}_2 \)), - 4 C-C single bonds (2 in the backbone of the molecule and 1 between \( \text{C}_2 \) and \( \text{C}_3 \)), - 1 C-H bond at the end of the molecule (for the \( \text{CH}_2 \) group). So, the total number of sigma bonds is 10.

2. Step 2: Count the pi bonds: The double bond between \( \text{C}_3 \) and \( \text{C}_4 \) consists of 1 sigma bond and 1 pi bond. Thus, the molecule contains 10 sigma bonds and 3 pi bonds.