What is Boiling Point

What is Boiling Point?

The boiling point is the temperature at which a liquid starts to boil and turns into gas.

Example: Water boils at 100°C (212°F) at normal atmospheric pressure.

Factors Affecting Boiling Point

1. Intermolecular Forces

• Stronger molecular bonds → Higher boiling point.
• Weaker molecular bonds → Lower boiling point.

2. External Pressure

• Higher pressure → Higher boiling point.
• Lower pressure → Lower boiling point.
• Example: Water boils at lower temperatures in high-altitude areas due to low pressure.

3. Altitude (Height Above Sea Level)

• Higher altitude → Lower boiling point (due to reduced atmospheric pressure).
• Lower altitude → Higher boiling point.
• Example: Water boils below 100°C in mountains but at exactly 100°C at sea level.

4. Impurities in Liquid

• Adding impurities (like salt) increases boiling point.
• Example: Saltwater boils at a higher temperature than pure water.

Key Takeaways

• Boiling point depends on molecular forces, pressure, altitude, and impurities.
• It is not always constant; it varies with environmental conditions.
• In vacuum (zero pressure), liquids boil at very low temperatures.
• In high pressure (like a pressure cooker), water boils at a temperature above 100°C.