In a compound

The number of sigma and pi bonds respectively are :`overset(NC)overset(|)underset(NC)underset(|)(C)=overset(M(CO)_(3))overset(|)underset(C_(2)H_(5))underset(|)(C)`

Options

A. `19,11`
B. `19, 5`
C. `13, 11`
D. `7, 3`

Answer

To determine the number of sigma (σ) and pi (π) bonds in the given compound, we will follow these steps:

### Step 1: Draw the Structure of the Compound
The compound consists of a central carbon atom connected to two cyanide groups (−C≡N) and an ethyl group (−C₂H₅). The structure can be visualized as follows:

```
C
/ \
C≡N C₂H₅
```

### Step 2: Identify the Types of Bonds
- **Cyanide Group (C≡N)**: Each cyanide group has a triple bond between carbon and nitrogen, which consists of 1 sigma bond and 2 pi bonds.
- **Ethyl Group (C₂H₅)**: The ethyl group has single bonds between carbon and hydrogen, which consist of only sigma bonds.

### Step 3: Count the Sigma Bonds
1. **Cyanide Groups**:
- Each cyanide (C≡N) contributes 1 sigma bond. Since there are 2 cyanide groups, they contribute a total of 2 sigma bonds.

2. **Ethyl Group**:
- The ethyl group (C₂H₅) has 5 C-H bonds and 1 C-C bond, contributing a total of 6 sigma bonds.

3. **Total Sigma Bonds**:
- From cyanide groups: 2
- From ethyl group: 6
- Total = 2 + 6 = **8 sigma bonds**.

### Step 4: Count the Pi Bonds
1. **Cyanide Groups**:
- Each cyanide (C≡N) contributes 2 pi bonds. Since there are 2 cyanide groups, they contribute a total of 4 pi bonds.

2. **Ethyl Group**:
- The ethyl group does not contribute any pi bonds as it only contains single bonds.

3. **Total Pi Bonds**:
- From cyanide groups: 4
- From ethyl group: 0
- Total = 4 + 0 = **4 pi bonds**.

### Conclusion
Thus, the number of sigma and pi bonds in the compound are:
- **Sigma bonds**: 8
- **Pi bonds**: 4

### Final Answer
The number of sigma and pi bonds respectively are **8 and 4**.

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