Number of sp Hybridised carbon in the given structure is
`CH_3CH_2CH=C=C=C=CH-C-=CH`

Options

A. 7
B. 5
C. 4
D. 6

Answer

To determine the number of sp hybridized carbon atoms in the given structure `CH₃CH₂CH=C=C=C=CH-C≡CH`, we will follow these steps:

### Step 1: Identify the Structure
The given structure is a hydrocarbon chain with multiple double and triple bonds. We will analyze each carbon atom in the chain to determine its hybridization.

### Step 2: Expand the Structure
The structure can be expanded as follows:
- The first part is `CH₃-CH₂-CH=`, which means the first three carbons are connected with single bonds and one double bond.
- Following this, we have `C=C=C=`, indicating three consecutive double bonds.
- Finally, we have `CH-C≡CH`, where the last two carbons are connected by a triple bond.

### Step 3: Count Sigma Bonds and Lone Pairs
To determine the hybridization of each carbon atom, we will count the number of sigma bonds (σ) and lone pairs (LP) for each carbon atom:
- **Carbon 1 (C1)**: CH₃ (3 σ bonds) → sp³
- **Carbon 2 (C2)**: CH₂ (2 σ bonds) → sp³
- **Carbon 3 (C3)**: CH= (1 σ bond + 1 π bond) → sp²
- **Carbon 4 (C4)**: C= (1 σ bond + 1 π bond) → sp²
- **Carbon 5 (C5)**: C= (1 σ bond + 1 π bond) → sp²
- **Carbon 6 (C6)**: C (1 σ bond + 1 π bond) → sp
- **Carbon 7 (C7)**: C (1 σ bond + 2 σ bonds from the triple bond) → sp
- **Carbon 8 (C8)**: C≡ (1 σ bond + 2 π bonds) → sp

### Step 4: Determine Hybridization
Now we summarize the hybridization:
- C1: sp³
- C2: sp³
- C3: sp²
- C4: sp²
- C5: sp²
- C6: sp
- C7: sp
- C8: sp

### Step 5: Count the sp Hybridized Carbons
From our analysis, we can see that:
- C6, C7, and C8 are sp hybridized.

Thus, the total number of sp hybridized carbon atoms is **3**.

### Final Answer
The number of sp hybridized carbon atoms in the given structure is **3**.

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