Third Term Lesson Note for Week Three
Class : Primary 5
Subject : Basic Science
Topic : Soap Making (Methods and materials used)
Duration : 40 minutes
Period : Single Period
Reference Book :
- Stan Basic Science and Technology for Primary Schools, Book 5
- Lagos State Unified Schemes of Work for Primary Schools, (Primary 4 – 6)
- Online Resources
Instructional Material : Pictorial chart of ingredients used in soap making
Learning Objectives : By the end of the lesson learners will be able to :
i. Describe the process of making soap and identify active ingredients used.
ii. Identify and explain the methods used in soap making.
iii. State the uses of soap
Previous Knowledge : Learners are familiar with acids and Bases .
Content :
Soap is a cleansing agent which produces foam or lather when mixed with water.
Soap is a substance produced by the chemical reaction of caustic potash or caustic soda with vegetable oil or animal fat. This chemical reaction is called saponification.
Saponification is simply the reaction between caustic potash or caustic soda and oil, which results in the formation of soap.
Other ingredients such as perfume, coloring, disinfectants and preservatives can also be added to soap.
Types of Soap.
There are basically two types of soap. These are : soft soap and hard soap
a. Soft Soap : This is form by the mixture of caustic potash (potassium hydroxide) and oil. They are often referred to as Potassium soap.
Examples of soft soap are liquid soap, toilet soap and antiseptic soap.
b. Hard Soap : is the mixture of caustic soda and oil, known as Sodium soap. Examples of hard soap are bar soap or key soap used in washing our clothes.
Local soap is made from palm oil and alkali which can be gotten from the burnt palm bunches or dried plantain husks.
In Nigeria , the local soap is a well-known as the black soap.
Processes of making local soap :
The following ingredients are required to make soap.
1. Water
2. Palm oil
3. Caustic soda or an alkali source, a source of heat.
Presentation Steps :
Step 1 : Revises the previous lesson taught with the learners by asking questions orally.
Step 2 : Introduces the new topic by describing soap and soap making. List the types of soap.
Step 3 : Explain the process of making soap and identify the ingredients used. Then state the use of soap.
Evaluation :
1. ____________ is a cleansing agent which produces foam or lather when mixed with water. (a) Stone (b) Soap (c) Sand
2. The process of mixing caustic soda or potash with oil to make soap is known as _______________. (a) Saponification (b) Specification (c) Substitution
3. Mention two types of soap.
i. ____________________ ii. ___________________
4. Which of these is an example of hard soap ? (a) liquid soap (b) bar soap (c) toilet soap
5. List three ingredients used in making Soap.
i. ____________________ ii. ___________________
iii. ___________________
Conclusion : At the end of the lesson, learners were able to answer the questions correctly.
Assignment :
State the process/ procedures of making local soap.