How many sigma and pi bonds are present in toluene ?

Options

A. `10 sigma and 3 pi " bonds" `
B. `12 sigma and 3 pi " bonds "`
C. ` 15 sigma and 3 pi " bonds "`
D. ` 6 sigma and 3 pi " bonds "`

Explanation

To find the number of sigma and pi bonds in toluene, we will first need to understand its structure. Toluene is a derivative of benzene, where one hydrogen atom on the benzene ring is replaced by a methyl group (–CH₃).

### Step-by-step Solution:

1. **Draw the Structure of Toluene**:
- Toluene consists of a benzene ring (C₆H₆) with a methyl group attached to one of the carbon atoms.
- The benzene ring has alternating double bonds, which can be represented as C₆H₅-CH₃.

2. **Identify the Bonds**:
- In the benzene ring, there are 6 carbon atoms. Each carbon atom is bonded to one hydrogen atom and is connected to two other carbon atoms.
- The structure can be represented as follows:
```
C
/ \
C C
|| ||
C---C
\ /
C
```
- The methyl group (–CH₃) is attached to one of the carbon atoms in the benzene ring.

3. **Count the Sigma Bonds**:
- Each single bond (C-H or C-C) is a sigma bond.
- In the benzene ring:
- There are 6 C-H bonds (one for each carbon).
- There are 6 C-C bonds (each carbon is connected to two other carbons).
- Therefore, the total number of sigma bonds in toluene:
- C-H bonds: 6
- C-C bonds in the benzene ring: 6
- C-C bond between the benzene ring and the methyl group: 1
- Total sigma bonds = 6 (C-H) + 6 (C-C in benzene) + 1 (C-C with methyl) = 13 sigma bonds.

4. **Count the Pi Bonds**:
- In the benzene ring, there are 3 double bonds, and each double bond consists of one sigma bond and one pi bond.
- Therefore, the total number of pi bonds in toluene is:
- Pi bonds from benzene = 3.
- Total pi bonds = 3.

5. **Final Count**:
- Total Sigma Bonds = 13
- Total Pi Bonds = 3

### Conclusion:
- Toluene has **13 sigma bonds** and **3 pi bonds**.