The number of `sigma`- and `pi`-bond in hexan-2,4-diol, respectively,is:

Options

A. 18,2
B. 17,2
C. 17,1
D. 18,1

Explanation

To determine the number of sigma (σ) and pi (π) bonds in hexan-2,4-diol, we follow these steps:

### Step 1: Understand the Structure of Hexan-2,4-diol
Hexan-2,4-diol is an organic compound with the following characteristics:
- It contains 6 carbon atoms (hexane).
- There are hydroxyl (OH) groups attached to the second and fourth carbon atoms.

### Step 2: Draw the Structure
The structure of hexan-2,4-diol can be represented as follows:

```
CH3-CH(OH)-CH2-CH(OH)-CH2-CH3
```

### Step 3: Count the Sigma Bonds
1. **Carbon-Carbon (C-C) Bonds**:
- There are 5 C-C bonds in the chain.

2. **Carbon-Hydrogen (C-H) Bonds**:
- Each carbon in the chain is bonded to enough hydrogens to satisfy the tetravalency of carbon.
- The terminal carbons (CH3) have 3 H each, and the internal carbons have 2 H each, except for the carbons with OH groups.
- Total C-H bonds:
- 2 terminal CH3 = 6 H
- 2 CH (with OH) = 1 H each = 2 H
- 2 CH2 (between CH and CH) = 2 H each = 4 H
- Total C-H = 6 + 2 + 4 = 12 C-H bonds.

3. **Carbon-Oxygen (C-O) Bonds**:
- Each OH group contributes 1 C-O bond.
- There are 2 OH groups, hence 2 C-O bonds.

### Step 4: Calculate Total Sigma Bonds
- Total σ bonds = C-C bonds + C-H bonds + C-O bonds
- Total σ bonds = 5 (C-C) + 12 (C-H) + 2 (C-O) = 19 σ bonds.

### Step 5: Count the Pi Bonds
- In hexan-2,4-diol, there are no double bonds present, which means there are no π bonds.

### Final Answer
The number of sigma (σ) bonds is 19 and the number of pi (π) bonds is 0.

### Summary
- **Number of σ bonds**: 19
- **Number of π bonds**: 0

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