TERM׃ 1ST TERM
WEEK SIX
Class: Senior Secondary School 2
Age: 16 years
Duration: 40 minutes of 5 periods each
Date:
Subject: Chemistry
Topic: CHEMICAL REACTION 3
SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to
INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures
INSTRUCTIONAL PROCEDURES
PERIOD 1-2
PRESENTATION |
TEACHER’S ACTIVITY |
STUDENT’S ACTIVITY |
STEP 1 INTRODUCTION |
The teacher explains chemical equilibrium to the students.
|
Students pay attention |
STEP 2 EXPLANATION |
He discusses the equilibrium constant.
|
Students pay attention and participates |
STEP 3 EXPLANATION |
Teacher explains the Le Chatelier’s principle and discuss the factors that affects it. |
Students pay attention and participates |
STEP 4 NOTE TAKING |
The teacher writes a summarized note on the board |
The students copy the note in their books |
NOTE
CHEMICAL REACTION 3
Chemical Equilibrium.
Chemical equilibrium is a state in a chemical reaction where the concentrations of reactants and products remain constant over time. This dynamic balance is achieved when the forward and reverse reactions occur at the same rate, resulting in no net change in the overall composition of the system.
Equilibrium Constant (K)
For a general reaction aA + bB cC + dD, the equilibrium constant (K) is given by the ratio of the product concentrations to the reactant concentrations, each raised to the power of their respective coefficients in the balanced chemical equation:
K = [C]c[D]d/[A]a [B]c
- If ( K > 1), the equilibrium favors the products.
- If ( K < 1), the equilibrium favors the reactants.
- If ( K = 1), the concentrations of products and reactants are roughly equal.
Law of Mass Action
The equilibrium constant expression is derived from the Law of Mass Action, which states that the rate of a chemical reaction is directly proportional to the product of the masses (concentrations) of the reacting substances, each raised to the power of their coefficients in the balanced chemical equation.
[ aA + bB cC + dD ]
Rate = k[A]a[B]b
Le Chatelier's Principle
Le Chatelier's Principle helps predict how a system at equilibrium responds to changes in temperature, pressure, or concentration. If an external change is applied, the system will adjust itself to partially counteract that change.
- Concentration Changes: If the concentration of a reactant or product is changed, the system adjusts by shifting the equilibrium position to oppose the change.
- Temperature Changes: If the temperature is increased, the equilibrium will shift in the endothermic or exothermic direction, depending on the reaction.
- Pressure Changes: For reactions involving gases, changes in pressure can be offset by shifts in the equilibrium position.
EVALUATION: - Discuss chemical equilibrium
- Give an equation for equilibrium constant k
- State Le chatelier’s principle.
CLASSWORK: As in evaluation
CONCLUSION: The teacher commends the students positively