Which of the correct increasing order of boiling points of the following compounds?
1-Iodobutane,1-Bromobutane,1-Chlorobutane, Butane

Options

A. Butanelt1-Chlorobutanelt1-Bromobutanelt1-Iodobutane
B. 1-Iodobutanelt1-Bromobutanelt1-ChlorobutaneltButane
C. Butanelt1-Iodobutanelt1-Bromobutanelt1-Chlorobutane
D. Butanelt1-Chlorobutanelt1-Iodobutanelt1-Bromobutane

Explanation

To determine the correct increasing order of boiling points for the compounds 1-Iodobutane, 1-Bromobutane, 1-Chlorobutane, and Butane, we will analyze the molecular weights and the factors affecting boiling points.

### Step-by-Step Solution:

1. **Identify the Compounds and Their Molecular Formulas**:
- 1-Iodobutane: C4H9I
- 1-Bromobutane: C4H9Br
- 1-Chlorobutane: C4H9Cl
- Butane: C4H10

2. **Calculate the Molar Mass of Each Compound**:
- 1-Iodobutane (C4H9I):
- C: 12.01 g/mol × 4 = 48.04 g/mol
- H: 1.008 g/mol × 9 = 9.072 g/mol
- I: 126.90 g/mol
- Total = 48.04 + 9.072 + 126.90 = **184.01 g/mol**

- 1-Bromobutane (C4H9Br):
- C: 12.01 g/mol × 4 = 48.04 g/mol
- H: 1.008 g/mol × 9 = 9.072 g/mol
- Br: 79.90 g/mol
- Total = 48.04 + 9.072 + 79.90 = **136.01 g/mol**

- 1-Chlorobutane (C4H9Cl):
- C: 12.01 g/mol × 4 = 48.04 g/mol
- H: 1.008 g/mol × 9 = 9.072 g/mol
- Cl: 35.45 g/mol
- Total = 48.04 + 9.072 + 35.45 = **92.56 g/mol**

- Butane (C4H10):
- C: 12.01 g/mol × 4 = 48.04 g/mol
- H: 1.008 g/mol × 10 = 10.08 g/mol
- Total = 48.04 + 10.08 = **58.12 g/mol**

3. **Analyze the Boiling Points**:
- The boiling point of a compound generally increases with an increase in molar mass due to stronger van der Waals forces (dispersion forces) in larger molecules.
- Based on the calculated molar masses:
- Butane: 58.12 g/mol
- 1-Chlorobutane: 92.56 g/mol
- 1-Bromobutane: 136.01 g/mol
- 1-Iodobutane: 184.01 g/mol

4. **Establish the Increasing Order of Boiling Points**:
- From the lowest to the highest boiling point:
- Butane < 1-Chlorobutane < 1-Bromobutane < 1-Iodobutane

### Final Answer:
The correct increasing order of boiling points is:
**Butane < 1-Chlorobutane < 1-Bromobutane < 1-Iodobutane**