Gas Laws: Boyle’s Law, Charles’ Law, Avogadro’s Law, Ideal Gas Law, etc.
Introduction:
Gas laws are the fundamental principles that explain the physics and behavior of gases. These laws help predict various properties of gases, such as pressure, volume, temperature, and concentration. There are several gas laws, including Boyle’s law, Charles’ law, Avogadro’s law, ideal gas law, etc.
Boyle’s Law:
- Explanation: Boyle’s law states that the pressure of a gas is inversely proportional to its volume at a constant temperature.
- Key Concept: As the volume of a gas increases, its pressure decreases, and vice-versa.
- Equation: P1V1 = P2V2 (where P is pressure and V is volume)
- Example: A gas in a closed container has a volume of 10 L at a pressure of 2 atm. What will be the pressure if the volume is reduced to 5 L?
Solution: P1V1 = P2V2; 2 atm x 10 L = P2 x 5 L; P2 = 4 atm - Reference: http://www.chem.purdue.edu/gchelp/howtosolveit/Gases/BoylesLaw.htm
Charles’ Law:
- Explanation: Charles’ law states that the volume of a gas is directly proportional to its temperature at a constant pressure.
- Key Concept: As the temperature of a gas increases, its volume increases, and vice-versa.
- Equation: V1/T1 = V2/T2 (where V is volume and T is temperature)
- Example: A gas at a temperature of 300 K has a volume of 10 L. What will be the volume at 500 K?
Solution: V1/T1 = V2/T2; 10 L/300 K = V2/500 K; V2 = 16.67 L - Reference: https://www.bbc.co.uk/bitesize/guides/zsdr4wx/revision/1
Avogadro’s Law:
- Explanation: Avogadro’s law states that the number of molecules or atoms of a gas is directly proportional to its volume at a constant pressure and temperature.
- Key Concept: As the number of gas molecules increases, its volume also increases proportionally.
- Equation: V1/n1 = V2/n2 (where V is volume and n is the number of molecules)
- Example: A sample of gas contains 2.5 x 10^23 molecules at a volume of 10 L. What will be the volume when the number of molecules increases to 4 x 10^23?
Solution: V1/n1 = V2/n2; 10 L/2.5 x 10^23 mol = V2/4 x 10^23 mol; V2 = 16 L - Reference: https://www.thoughtco.com/avogadros-law-definition-examples-373319
Ideal Gas Law:
- Explanation: The ideal gas law combines Boyle’s law, Charles’ law, and Avogadro’s law to predict the behavior of gases at any given condition.
- Key Concept: The ideal gas law equation shows how pressure, volume, temperature, and number of molecules of a gas are related.
- Equation: PV = nRT (where P is pressure, V is volume, n is the number of molecules, R is the gas constant, and T is temperature in Kelvin)
- Example: What is the pressure of a gas sample with a volume of 2 L, containing 3 moles of gas at a temperature of 300 K?
Solution: PV = nRT; P x 2 L = 3 mol x 0.08206 L atm/mol K x 300 K; P = 61.23 atm - Reference: https://www.chem.ucla.edu/harding/IGL/ordinary.html
Conclusion:
Gas laws play a vital role in understanding the behavior of gases. The knowledge of gas laws helps in solving numerous problems in industries like chemical, petroleum, and environmental. It is essential to understand these laws to comprehend the underlying concept of various industrial processes and to design efficient systems.
