Which is the correct increasing order of boiling points of the following compounds?
1-Bromoethane,1-Bromopropane,1-Bromobutane,Bromobenzene

Options

A. Bromobenzenelt1-Bromobutanelt1-Bromopropanelt1-Bromoethane
B. Bromobenzenelt1-Bromoethanelt1-Bromopropane,1-Bromobutane
C. 1-Bromopropanelt1-Bromobutanelt1-BromoethaneltBromobenzene
D. 1-Bromoethanelt1-Bromopropanelt1-BromobutaneltBromobenzene

Explanation

To determine the correct increasing order of boiling points for the compounds 1-Bromoethane, 1-Bromopropane, 1-Bromobutane, and Bromobenzene, we need to analyze the structure and size of the hydrocarbon chains in these compounds.

### Step-by-Step Solution:

1. **Identify the Compounds and Their Structures**:
- 1-Bromoethane (C2H5Br) has a 2-carbon chain.
- 1-Bromopropane (C3H7Br) has a 3-carbon chain.
- 1-Bromobutane (C4H9Br) has a 4-carbon chain.
- Bromobenzene (C6H5Br) has a benzene ring (6 carbon atoms in a cyclic structure).

2. **Understand the Factors Affecting Boiling Points**:
- Boiling points of haloalkanes generally increase with the increase in the size of the hydrocarbon chain due to greater van der Waals forces (dispersion forces).
- Aromatic compounds like bromobenzene typically have higher boiling points than aliphatic compounds due to their stable ring structure and larger surface area.

3. **Compare the Hydrocarbon Chain Sizes**:
- 1-Bromoethane: 2 carbons
- 1-Bromopropane: 3 carbons
- 1-Bromobutane: 4 carbons
- Bromobenzene: 6 carbons (but in a different structure)

4. **Order the Compounds Based on Chain Size**:
- As the number of carbons increases, the boiling point increases. Therefore, we can arrange the compounds based on the size of their hydrocarbon chains:
- 1-Bromoethane < 1-Bromopropane < 1-Bromobutane < Bromobenzene

5. **Conclusion**:
- The correct increasing order of boiling points is:
- 1-Bromoethane < 1-Bromopropane < 1-Bromobutane < Bromobenzene

### Final Answer:
The correct increasing order of boiling points is:
**1-Bromoethane < 1-Bromopropane < 1-Bromobutane < Bromobenzene**