How many chiral structure isomers of alcohols are possible by molecular formula `C_5H_10O`?

Explanation

To determine how many chiral structure isomers of alcohols are possible with the molecular formula \( C_5H_{10}O \), we will follow these steps:

### Step 1: Identify the Type of Compound
Since the compound is an alcohol, it contains one hydroxyl group (-OH). The molecular formula indicates that it is a monohydric alcohol.

### Step 2: Determine the Structural Isomers
We need to find all possible structural isomers of \( C_5H_{10}O \). This involves varying the carbon skeleton and the position of the -OH group.

1. **Straight-chain alcohols**:
- Pentan-1-ol
- Pentan-2-ol
- Pentan-3-ol
- Pentan-4-ol (not valid as it would lead to a non-alcoholic structure)

2. **Branched-chain alcohols**:
- 2-Methylbutan-1-ol
- 3-Methylbutan-1-ol
- 2-Methylbutan-2-ol
- 3-Pentanol

### Step 3: Count the Total Structural Isomers
From our analysis, we find the following structural isomers:
- Pentan-1-ol
- Pentan-2-ol
- Pentan-3-ol
- 2-Methylbutan-1-ol
- 3-Methylbutan-1-ol
- 2-Methylbutan-2-ol
- 3-Pentanol

This gives us a total of **7 structural isomers**.

### Step 4: Identify Chiral Centers
Next, we need to identify which of these isomers have chiral centers. A chiral center is typically a carbon atom that is bonded to four different groups.

1. **Pentan-2-ol**: Chiral center at C2 (attached to -OH, -CH3, -H, and -C3H7).
2. **Pentan-3-ol**: Chiral center at C3 (attached to -OH, -C2H5, -H, and -C4H9).
3. **2-Methylbutan-2-ol**: Chiral center at C2 (attached to -OH, -CH3, -C4H9, and -C3H7).

### Step 5: Count the Chiral Isomers
From the analysis, we find that there are **3 chiral structure isomers**:
- Pentan-2-ol
- Pentan-3-ol
- 2-Methylbutan-2-ol

### Final Answer
Thus, the total number of chiral structure isomers of alcohols possible with the molecular formula \( C_5H_{10}O \) is **3**.

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