Ideal Gas Law and Its History: Crash Course Chemistry Notes

Introduction to Gases

• Gases are everywhere: in space, on planets, in blood, and in soda.
• We live submerged in a sea of gas; can feel it by waving our hands.

Gas Behavior: Simplistic and Complex

• Good News: Easy to describe theoretically, experimentally, and mathematically.
• Bad News: Gases almost never behave ideally.

Boyle’s Law

• First Mathematical Description: Link between pressure and volume.
• Boyle’s Law: For a constant temperature and gas amount, Pressure (P) x Volume (V) = Constant (k).
• Real Credit: Richard Townley and Henry Power. Boyle attributed Townley's hypothesis and published it.

Key Contributors to Gas Laws

• Boyle (Townley and Power): Pressure x Volume = Constant (k).
• Jacques Charles: Volume / Temperature = Constant (k) at constant pressure.
• Amedeo Avogadro: Volume / Number of Moles = Constant (k) at constant pressure and temperature.

Ideal Gas Law

• Derivation: All individual laws combine into one equation.
• Equation: PV = nRT
  • P: Pressure
  • V: Volume
  • n: Number of moles
  • R: Universal Gas Constant (8.3145 L·kPa/(K·mol))
  • T: Temperature (Kelvin)

Variables in the Ideal Gas Law

• Pressure (P): Force per area (measured in pascals or kilopascals).
• Volume (V): Amount of space gas particles occupy.
• Number of Moles (n): Amount of gas in the system.
• Universal Gas Constant (R): 8.3145 L·kPa/(K·mol), not truly universal or constant.
• Temperature (T): Kinetic energy at the atomic level.

Real-World Application and Demonstration

• Demonstration with a Soda Can: Boiling water turns to vapor, condenses in ice water, pressure drops inside can and it crushes itself.
• Explanation Using Ideal Gas Law: Decrease in temperature and number of moles leads to decrease in pressure and volume.

Limitations of Ideal Gas Law

• Non-Ideal Behavior: Deviations at low temperatures or high pressures.

Jargon and Important Concepts

• STP (Standard Temperature and Pressure): 0°C and 100 kPa. One mole of ideal gas occupies 22.4 liters at STP.
• Absolute Zero: Temperature where particle movement stops (-273.15°C or 0 Kelvin).

Conclusion

• Summary: Contributions to the ideal gas law, understanding the equation, and key terminologies.
• Credits: The team behind Crash Course Chemistry.