Chemical Equilibrium In One Shot - JEE/NEET/Class 11th Boards | Victory Batch

Introduction

This tutorial provides a comprehensive overview of chemical equilibrium, based on the video "Chemical Equilibrium In One Shot." It is designed for students preparing for JEE, NEET, or Class 11th Boards and covers essential concepts, laws, and principles related to chemical reactions and equilibrium.

Step 1: Understanding Equilibrium

• Definition: Equilibrium in chemistry refers to a state in a reversible reaction where the rate of the forward reaction equals the rate of the reverse reaction.
• Importance: This balance allows for a stable concentration of reactants and products over time.

Step 2: Types of Chemical Reactions

• Combination Reactions: Two or more reactants combine to form a single product.
• Decomposition Reactions: A single compound breaks down into two or more simpler substances.
• Displacement Reactions: An element replaces another in a compound.
• Redox Reactions: Involves the transfer of electrons between substances, resulting in changes in oxidation states.

Step 3: Law of Mass Action

• Principle: At equilibrium, the rate of a reaction is proportional to the product of the concentrations of the reactants, each raised to the power of their coefficients in the balanced equation.
• Equation: For a reaction aA + bB ⇌ cC + dD, the expression is: [ K_c = \frac{[C]^c [D]^d}{[A]^a [B]^b} ]

Step 4: Characteristics of Equilibrium Constant

• Independence: The equilibrium constant (K) is constant at a given temperature, regardless of the initial concentrations.
• Temperature Dependence: Changes in temperature can alter the value of K.

Step 5: Reaction Quotient and Equilibrium Constant

• Reaction Quotient (Q): Used to determine the direction in which a reaction will proceed to reach equilibrium.
• Comparison: If Q < K, the reaction shifts to the right (toward products). If Q > K, it shifts to the left (toward reactants).

Step 6: Degree of Dissociation

• Definition: The fraction of a reactant that has dissociated into products at equilibrium.
• Calculation: For a dissociation reaction, the degree of dissociation can be expressed as: [ \alpha = \frac{\text{number of moles dissociated}}{\text{initial number of moles}} ]

Step 7: Relative Density and Degree of Dissociation

• Relative Density: The ratio of the density of a substance to the density of a reference substance (usually water).
• Application: Helps in understanding the extent of reactions and their equilibria.

Step 8: Le-Chatelier’s Principle

• Principle: If a system at equilibrium is subjected to a change in concentration, pressure, or temperature, the equilibrium will shift to counteract that change.
• Applications:
  • Increasing concentration of reactants shifts the equilibrium to the right.
  • Increasing pressure shifts the equilibrium towards the side with fewer moles of gas.

Step 9: Characteristics of Equilibrium

• Dynamic Nature: Equilibrium is a dynamic state; reactions continue to occur, but there is no net change in concentrations.
• Macroscopic Observations: At equilibrium, properties such as color, pressure, and concentration remain constant.

Conclusion

Understanding chemical equilibrium is crucial for success in chemistry-related exams. Key concepts include the types of reactions, the law of mass action, equilibrium constants, and Le-Chatelier’s principle. For further study, consider practicing problems related to these principles and reviewing additional resources to solidify your knowledge.