The number of sigma bonds in
`CH_(2)=CH - CH = CH - C -= CH` is _________.

Options

A. 5
B. 9
C. 11
D. 10

Answer

To determine the number of sigma bonds in the compound \( CH_2=CH-CH=CH-C \equiv CH \), we will analyze the structure step by step.

### Step 1: Identify the structure
The given compound can be expanded as follows:
- The first carbon (C) has two hydrogens (H) and is double bonded to the second carbon (C).
- The second carbon is single bonded to the third carbon (C), which is again double bonded to the fourth carbon (C).
- The fourth carbon is single bonded to the fifth carbon (C), which is triple bonded to the last carbon (C).

### Step 2: Count the types of bonds
1. **Single Bonds (Sigma Bonds)**:
- Each single bond consists of one sigma bond.
- Between the first and second carbon (C1-C2): 1 sigma bond
- Between the second and third carbon (C2-C3): 1 sigma bond
- Between the third and fourth carbon (C3-C4): 1 sigma bond
- Between the fourth and fifth carbon (C4-C5): 1 sigma bond
- Between the fifth carbon and the last carbon (C5-C6): 1 sigma bond

2. **Double Bonds (Sigma and Pi Bonds)**:
- Each double bond consists of one sigma bond and one pi bond.
- Between the first and second carbon (C1=C2): 1 sigma bond
- Between the third and fourth carbon (C3=C4): 1 sigma bond

3. **Triple Bonds (Sigma and Pi Bonds)**:
- Each triple bond consists of one sigma bond and two pi bonds.
- Between the fifth carbon and the last carbon (C5≡C6): 1 sigma bond

### Step 3: Total the sigma bonds
Now, let’s sum up all the sigma bonds:
- From single bonds: 5 sigma bonds
- From double bonds: 2 sigma bonds
- From triple bonds: 1 sigma bond

Total sigma bonds = 5 (from single bonds) + 2 (from double bonds) + 1 (from triple bond) = 8 sigma bonds.

### Final Answer
The total number of sigma bonds in the compound \( CH_2=CH-CH=CH-C \equiv CH \) is **8**.

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