Class 11th Chemistry-Chapter 3 – Gases

Full Chapter Notes

Exercise

MCQ’s

Class 11th Chemistry Chapter 3, Gases, focuses on the properties and behavior of gases, including their laws and applications. Here’s a general overview:

1. Nature of Gases:
   • Gases have no fixed shape or volume; they expand to fill their container.
   • The particles in a gas are widely spaced and move freely, leading to low density and high compressibility.
2. Gas Laws:
   • Boyle’s Law: States that the pressure of a gas is inversely proportional to its volume at constant temperature. (P1V1 = P2V2)
   • Charles’s Law: States that the volume of a gas is directly proportional to its absolute temperature at constant pressure. (V1/T1 = V2/T2)
   • Avogadro’s Law: States that equal volumes of gases at the same temperature and pressure contain an equal number of molecules. (V1/n1 = V2/n2)
3. Ideal Gas Equation:
   • The ideal gas law combines the above laws: PV = nRT, where:
     • P = pressure
     • V = volume
     • n = number of moles
     • R = universal gas constant
     • T = temperature (in Kelvin)
4. Real Gases:
   • Discussion on the behavior of real gases and how they deviate from ideal behavior under high pressure and low temperature.
   • The van der Waals equation corrects the ideal gas law for real gases, taking into account intermolecular forces and molecular volumes.
5. Kinetic Molecular Theory (KMT):
   • Explanation of the kinetic molecular theory, which describes the behavior of gases based on the motion of their particles.
   • Assumptions include that gas particles are in constant random motion and that collisions between particles are elastic.
6. Gas Mixtures:
   • Understanding Dalton’s Law of Partial Pressures, which states that the total pressure of a gas mixture is the sum of the partial pressures of its individual components.
7. Graham’s Law of Effusion:
   • Explains the relationship between the rates of effusion of two gases and their molar masses. Lighter gases effuse faster than heavier gases.
8. Applications:
   • Practical applications of gas laws in various fields such as chemistry, engineering, and environmental science.

This chapter provides essential insights into the behavior of gases, their properties, and their applications, laying the groundwork for further studies in chemistry and related disciplines.