Step 1: Understanding the Question:
Boiling point of organic compounds depends on molecular mass and surface area (branching).
Step 3: Detailed Explanation:
1. Molecular Mass: Higher molecular mass leads to stronger van der Waals forces. Pentan-1-ol, 3-methylbutan-1-ol, and 2,2-dimethylpropan-1-ol are isomers with formula \( \text{C}_5\text{H}_{12}\text{O} \), while Butan-1-ol is \( \text{C}_4\text{H}_{10}\text{O} \). Butan-1-ol has the lowest BP.
2. Branching: Among isomers, the straight-chain isomer has the highest surface area and strongest van der Waals forces. Branching decreases the surface area and weakens these forces.
Comparing the \( \text{C}_5 \) isomers:
- Pentan-1-ol: Linear chain (Highest BP).
- 3-Methylbutan-1-ol: One branch.
- 2,2-Dimethylpropan-1-ol: Highly branched (Lowest BP among isomers).
Therefore, Pentan-1-ol has the highest boiling point.
Step 4: Final Answer:
The compound with the highest boiling point is Pentan-1-ol.