Lesson Notes By Weeks and Term - Senior Secondary 2

TERM׃ 1^ST TERM

WEEK FIVE

Class: Senior Secondary School 2

Age: 16 years

Duration: 40 minutes of 5 periods each

Date:        

Subject: Chemistry

Topic: CHEMICAL REACTION 2

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

1. Explain the factors affecting the rate chemical reaction.
2. Identify the types of reaction.

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

PRESENTATION	TEACHER’S ACTIVITY	STUDENT’S ACTIVITY
STEP 1 INTRODUCTION	The teacher discusses factors affecting the rate chemical reaction.	Students pay attention
STEP 2 EXPLANATION	He explains the types of chemical reactions to the students.	Students pay attention and participates
STEP 3 NOTE TAKING	The teacher writes a summarized note on the board	The students copy the note in their books

 

NOTE

CHEMICAL REACTION 2

Factors affecting the rate of chemical reaction.

The rate of a chemical reaction is influenced by several factors:

1. Temperature: Generally, higher temperatures increase reaction rates by providing more kinetic energy to the reacting particles, leading to more frequent and energetic collisions.
2. Concentration of Reactants: Higher concentrations of reactants often result in more collisions between particles, increasing the likelihood of successful collisions and speeding up the reaction.
3. Surface Area: In reactions involving solids, a larger surface area provides more contact points for collisions, accelerating the reaction. This is particularly relevant for substances in powder or finely divided form.
4. Catalysts: Catalysts are substances that increase the rate of a reaction without being consumed. They provide an alternative reaction pathway with lower activation energy, making it easier for the reaction to occur.
5. Pressure: For gaseous reactions, an increase in pressure can enhance the reaction rate by decreasing the volume available for the gas particles, leading to more frequent collisions.

Types of chemical reactions

Chemical reactions are typically categorized into two main types: exothermic reactions and endothermic reactions.

1. Exothermic Reactions:

   - Definition: Exothermic reactions release energy to the surroundings in the form of heat, light, or sound.

   - Characteristics:

     - The products have lower energy than the reactants.

     - Heat is often a product in the reaction.

     - Examples include combustion reactions, such as burning wood or the reaction between acids and bases.

2. Endothermic Reactions:

   - Definition: Endothermic reactions absorb energy from the surroundings, resulting in a decrease in temperature.

   - Characteristics:

     - The products have higher energy than the reactants.

     - Heat is absorbed from the surroundings during the reaction.

     - Examples include photosynthesis in plants, where energy from sunlight is absorbed to convert carbon dioxide and water into glucose.

NOTE: In both types of reactions, the law of conservation of energy holds. This law states that energy cannot be created or destroyed but can only change forms. Therefore, in exothermic reactions, the energy released by the system is gained by the surroundings, and in endothermic reactions, energy is absorbed from the surroundings.

EVALUATION: - Enumerate 4 factors affecting the rate of chemical reaction.

                           - Identify the two types of chemical reaction and explain briefly.

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively