Arrange the following compounds in increasing order of boiling point :
Prpane-1-ol, butan-1-ol, butan-2-ol, pentan-1-ol

Options

A. Propan-1- ol, butan -1-ol, butan-1-ol, pentan -1-ol
B. Pentan-1-ol,butan-2-ol, butan-1-ol,propan -1-ol
C. Pentan-1-ol,butan- 2- ol, butan -1-ol, propan-1-ol
D. Pentan-1-ol,butan-1-ol, butan-2-ol,propan-1-ol

Explanation

To arrange the compounds propane-1-ol, butan-1-ol, butan-2-ol, and pentan-1-ol in increasing order of boiling points, we can follow these steps:

### Step 1: Understand the Factors Affecting Boiling Points
The boiling point of alcohols is influenced by:
- Molecular weight: Generally, higher molecular weight leads to higher boiling points.
- Structure: Among isomers, primary alcohols (1°) typically have higher boiling points than secondary (2°) and tertiary (3°) alcohols due to less steric hindrance and better hydrogen bonding.

### Step 2: Analyze Each Compound
1. **Propane-1-ol (C3H8O)**: This is a primary alcohol with a lower molecular weight (60 g/mol).
2. **Butan-1-ol (C4H10O)**: This is also a primary alcohol with a higher molecular weight (74 g/mol) than propane-1-ol.
3. **Butan-2-ol (C4H10O)**: This is a secondary alcohol with the same molecular weight as butan-1-ol (74 g/mol), but it generally has a lower boiling point than primary alcohols of the same molecular weight.
4. **Pentan-1-ol (C5H12O)**: This is a primary alcohol with a higher molecular weight (88 g/mol) than both butan-1-ol and butan-2-ol.

### Step 3: Compare the Boiling Points
Based on the factors discussed:
- Propane-1-ol will have the lowest boiling point due to its lower molecular weight.
- Butan-2-ol will have a higher boiling point than propane-1-ol but lower than butan-1-ol because it is a secondary alcohol.
- Butan-1-ol will have a higher boiling point than butan-2-ol due to being a primary alcohol.
- Pentan-1-ol will have the highest boiling point due to its higher molecular weight.

### Step 4: Arrange the Compounds
Thus, the increasing order of boiling points is:
1. Propane-1-ol
2. Butan-2-ol
3. Butan-1-ol
4. Pentan-1-ol

### Final Answer
**Increasing order of boiling points**: Propane-1-ol < Butan-2-ol < Butan-1-ol < Pentan-1-ol

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