Question

rank the following molecules in terms of increasing boiling point: • c₃h₇oh • licl • n₂ • c₄h₈ ○ n₂ < c₄h₈ < c₃h₇oh < licl ○ licl < c₄h₈ < c₃h₇oh < n₂ ○ licl < c₄h₈ < n₂ < c₃h₇oh ○ n₂ < licl < c₃h₇oh < c₄h₈ ○ c₃h₇oh < c₄h₈ n₂ < licl

Explanation:

Step1: Analyze Intermolecular Forces

• \( \text{N}_2 \): Nonpolar molecule, only London dispersion forces (LDF). Small molar mass, weak LDF.
• \( \text{C}_4\text{H}_8 \): Nonpolar (alkene), LDF. Larger molar mass than \( \text{N}_2 \), stronger LDF than \( \text{N}_2 \).
• \( \text{C}_3\text{H}_7\text{OH} \): Polar molecule, has hydrogen bonding (due to -OH group), plus LDF and dipole - dipole. Stronger intermolecular forces than nonpolar molecules.
• \( \text{LiCl} \): Ionic compound, ionic bonds (strongest intermolecular force type here), requires high energy to break.

Step2: Relate Forces to Boiling Point

Boiling point is proportional to the strength of intermolecular forces. Weaker forces → lower boiling point; stronger forces → higher boiling point.

• Weakest: \( \text{N}_2 \) (LDF, small mass)
• Next: \( \text{C}_4\text{H}_8 \) (LDF, larger mass than \( \text{N}_2 \))
• Next: \( \text{C}_3\text{H}_7\text{OH} \) (H - bonding)
• Strongest: \( \text{LiCl} \) (ionic bonds)

So the order of increasing boiling point is \( \text{N}_2 < \text{C}_4\text{H}_8 < \text{C}_3\text{H}_7\text{OH} < \text{LiCl} \).

Answer:

A. \( \text{N}_2 < \text{C}_4\text{H}_8 < \text{C}_3\text{H}_7\text{OH} < \text{LiCl} \) (where A is the first option in the list of choices)