Acids and Bases Lesson Note for Primary 5 Third Term Week 2

Basic Science Lesson Note

Class: Primary 5
Term: Third Term
Week: 2
Age: 9–10 years
Subject: Basic Science
Topic: Acids and Bases
Sub-topic: Meaning, Properties, and Common Examples of Acids and Bases
Duration: 40 minutes

Behavioural Objectives:

By the end of the lesson, pupils should be able to:

1. Define acids and bases.

2. List examples of acids and bases.

3. State the properties of acids and bases.

4. Identify common acidic and basic household substances.

5. Demonstrate how to test acids and bases using natural indicators.

Keywords:

Acid, Base, Bitter, Sour, Litmus paper, Neutral, Properties, Taste, Household substances, Indicators.

Set Induction (Introduction):

The teacher brings a lemon and a bar of soap to class and asks the pupils to describe the taste of lemon and the feel of soap. This sparks curiosity about the different nature of substances we use daily.

Entry Behaviour:

Pupils can mention various food items and cleaning substances they have used at home.

Learning Resources and Materials:

• Lemon juice

• Vinegar

• Soap solution

• Water

• Litmus papers (red and blue)

• Tumeric water (natural indicator)

• Chart showing examples of acids and bases

• Whiteboard and marker

Building Background / Connection to Prior Knowledge:

Pupils have already learned about liquids and their characteristics in previous terms and know that different substances have different tastes and reactions.

Embedded Core Skills:

• Observation

• Experimentation

• Communication

• Critical Thinking

Content of the Lesson:

Meaning of Acids:

• Acids are substances that have a sour taste.

• They turn blue litmus paper red.

• Acids are found in some foods and household products.

Examples of acids:

1. Lemon juice

2. Vinegar

3. Orange juice

4. Tomato

5. Pineapple juice

6. Battery acid

7. Carbonated drinks (e.g. Pepsi, Coke)

Meaning of Bases:

• Bases are substances that have a bitter taste and slippery feel.

• They turn red litmus paper blue.

• Bases are common in cleaning products.

Examples of bases:

1. Soap

2. Baking soda

3. Toothpaste

4. Ash

5. Caustic soda

6. Detergent

7. Bleach

Properties of Acids:

• Sour taste

• Turns blue litmus paper red

• Found in fruits and drinks

• Corrosive (strong acids)

• React with bases to form water and salt

Properties of Bases:

• Bitter taste

• Slippery feel

• Turns red litmus paper blue

• React with acids to form water and salt

• Can be harmful in concentrated forms

Simple Class Experiment:

Objective: To test substances using litmus paper.

Materials:

• Lemon juice

• Soap solution

• Red and blue litmus papers

Procedure:

1. Dip blue litmus paper into lemon juice — it turns red.

2. Dip red litmus paper into soap solution — it turns blue.

Conclusion: Acids turn blue litmus paper red while bases turn red litmus paper blue.

Class Activity Discussion (10 FAQs with Answers)

1. What is an acid?
   A substance with a sour taste that turns blue litmus paper red.

2. Name two examples of acids.
   Lemon juice, Vinegar.

3. What is a base?
   A substance with a bitter taste and slippery feel that turns red litmus paper blue.

4. Give two examples of bases.
   Soap, Toothpaste.

5. What is a property of acids?
   They taste sour.

6. What is a property of bases?
   They taste bitter.

7. What happens when you put blue litmus paper in acid?
   It turns red.

8. What happens when you put red litmus paper in a base?
   It turns blue.

9. Name one fruit that is acidic.
   Orange.

10. Mention a household cleaning product that is basic.
    Detergent.

Teacher’s and Learners’ Activities

Teacher’s Activities:

• Explains the meaning of acids and bases.

• Lists examples and demonstrates their properties.

• Guides pupils through simple litmus paper experiments.

Learners’ Activities:

• Listen attentively.

• Participate in class discussions.

• Observe the demonstration.

• Answer questions.

• Perform the test with teacher’s guidance.

Evaluation Questions (10 fill-in-the-gap questions with options)

1. Substances with a sour taste are called _______.
   a) Bases b) Acids c) Salts d) Waters

2. Lemon juice is an example of a(n) _______.
   a) Acid b) Base c) Neutral substance d) Solid

3. Acids turn _______ litmus paper red.
   a) Red b) Blue c) White d) Yellow

4. Substances with a bitter taste are called _______.
   a) Acids b) Bases c) Waters d) Liquids

5. Soap solution turns _______ litmus paper blue.
   a) Red b) Blue c) White d) Green

6. Toothpaste is an example of a _______.
   a) Base b) Acid c) Salt d) Gas

7. The substance that turns blue litmus paper red is called _______.
   a) Base b) Salt c) Acid d) Water

8. Substances that feel slippery are known as _______.
   a) Acids b) Bases c) Gases d) Liquids

9. _______ is a fruit that contains acid.
   a) Orange b) Soap c) Toothpaste d) Salt

10. Which of these is a property of bases?
    a) Bitter taste b) Sour taste c) Sweet taste d) No taste

Answer Key:

1. b 2. a 3. b 4. b 5. a 6. a 7. c 8. b 9. a 10. a

Conclusion:

The teacher revises the lesson, goes around to mark pupils’ work, corrects mistakes, and provides feedback.