In the hydrocarbon
`underset(6)(CH_(3))-underset(5)(C) equiv underset(4)(CH) - underset(3)overset(CH_(3))overset(|)(CH) - underset(2)(C )equiv underset(1)(CH)`
the state of hybridizaton of carbon 1,3 and 5 are in the following sequence

Options

A. `sp^(3), sp^(2), sp`
B. `sp^(2) , sp , sp^(3)`
C. sp, `sp^(3), sp`
D. `sp, sp^(2), sp^(3)`

Answer

To determine the hybridization states of carbon atoms 1, 3, and 5 in the given hydrocarbon structure, we will analyze each carbon atom step by step.

### Step 1: Identify the Structure
The hydrocarbon is represented as:
```
CH3
|
CH ≡ C - CH - C ≡ CH
```
Here, we need to analyze carbon atoms 1, 3, and 5.

### Step 2: Analyze Carbon 1
- **Connections**: Carbon 1 (C1) is connected to one hydrogen atom and is involved in a triple bond with carbon 2 (C2).
- **Bonds**:
- 1 σ bond with H
- 2 π bonds with C2 (from the triple bond)
- **Hybridization**:
- The steric number (number of σ bonds + lone pairs) is 2 (1 σ bond with H + 1 σ bond with C2).
- Since there are 2 regions of electron density, the hybridization of C1 is **sp**.

### Step 3: Analyze Carbon 3
- **Connections**: Carbon 3 (C3) is connected to one hydrogen atom and two other carbon atoms (C2 and C4).
- **Bonds**:
- 4 σ bonds (1 with H, 1 with C2, and 2 with C4)
- **Hybridization**:
- The steric number is 4 (4 σ bonds and no lone pairs).
- Therefore, the hybridization of C3 is **sp³**.

### Step 4: Analyze Carbon 5
- **Connections**: Carbon 5 (C5) is connected to one hydrogen atom and is involved in a triple bond with carbon 4 (C4).
- **Bonds**:
- 1 σ bond with H
- 2 π bonds with C4 (from the triple bond)
- **Hybridization**:
- The steric number is 2 (1 σ bond with H + 1 σ bond with C4).
- Thus, the hybridization of C5 is **sp**.

### Final Sequence of Hybridization
- C1: sp
- C3: sp³
- C5: sp

### Conclusion
The sequence of hybridization for carbon atoms 1, 3, and 5 is **sp, sp³, sp**.

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