Boiling Point

The boiling point of a substance is the temperature at which the vapor pressure of the liquid equals the external pressure surrounding the liquid. At this temperature, the liquid turns into vapor, and the bubbles of vapor form throughout the liquid.

Factors Affecting Boiling Point

Several factors can affect the boiling point of a substance:

• Pressure: An increase in pressure raises the boiling point, while a decrease in pressure lowers it.
• Intermolecular forces: Substances with stronger intermolecular forces tend to have higher boiling points.
• Molecular weight: Heavier molecules generally have higher boiling points than lighter ones.

Study Guide

To understand the concept of boiling point, consider the following key points:

1. Define boiling point and understand the relationship between vapor pressure and external pressure at the boiling point.
2. Learn how pressure affects the boiling point of a substance and be able to explain the concept using examples.
3. Understand the role of intermolecular forces in determining the boiling point of a substance and be able to compare the boiling points of different substances based on their intermolecular forces.
4. Study the impact of molecular weight on boiling point and be able to predict the boiling points of similar substances based on their molecular weights.
5. Practice solving problems related to boiling point, such as calculating the boiling point of a substance under different pressure conditions.