Third Term Lesson Note for Week Two
Class : Primary 5
Subject : Basic Science and Technology
Topic : Acids and Bases
Duration : 40 minutes
Period : Double Periods
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
Learning Objectives : By the end of the lesson learners will be able to :
i. Define Acids and Bases and list examples
ii. State the properties of acids and bases
iii. Mention uses of Acids and Bases
Content :
Acids and Bases
Acids are substances which are capable of changing blue litmus paper to red. Acids can occur naturally or be made by man in the laboratory.
Acids that occur naturally are called Organic acids. Examples of organic acids are Lactic acid (in milk) , Citric acid ( in unripe fruits), Acetic acid (vinegar).
Inorganic acids are the acids made by man in the laboratory. Examples are : Hydrochloric acid (HCl), Trioxonitrate (V) acid (HNO3), Tetraoxosulphate (VI) acid (H2SO4), Tetraoxocarbonate (IV) acid (HCO3)
Properties of an acid
1. Acids turn blue litmus paper red.
2. They have sour taste.
3. The concentrated acids can damage plastic and metals
4. The concentrated acids are corrosive (harmful, it burns)
5. They neutralize bases to form salt and water.
Uses of Acids.
i. Acids are used in the laboratory to produce other chemicals.
ii. They are used in the manufacturing of paints, fertilizer and drugs in industries.
iii. They can be used to produce salt when reacted with bases.
Iv. They are used in the production of important gazes such as hydrogen carbon dioxide, etc .
v. They are used as solvents.
Bases
Bases are substances which react with an acid to form salt and water only. They form solution that turns red litmus paper to blue.
Types of Bases
The two types of bases are :
1. Soluble bases : These are bases that are soluble in water. They are also called alkalis. Examples are sodium hydroxide (caustic soda), potassium hydroxide (caustic potash) and ammonium hydroxide
2. Insoluble bases : These are bases that are not soluble in water. For example, copper (II) oxide and Zinc oxide
Properties of bases
1. Bases turn red litmus paper to blue.
2. They have bitter taste.
3. They have a slippery or soapy feel when rubbed between the fingers
4. Concentrated bases are corrosive
5. They neutralize to form salt and water.
Uses of Bases
i. Bases are used to make soap.
ii. They are used in the production of other chemicals.
iii. They are used in the production of salt when they are mixed with acids.
iv. Calcium hydroxide (lime water) , is used in the production of POP (Plaster of Paris).
Some bases are used in the production of glass, detergents, drugs, etc.
Presentation Steps :
Step 1 : Revision of the previous lesson with the learners by asking them questions orally.
Step 2 : Introduces the new topic by defining acids and Bases, list examples and types
Step 3 : The teacher then state the properties of acids and Bases. He/ she also state their uses.
Evaluation :
1. ___________ are substances that is capable of turning blue litmus paper to red. (a) Bases (b) Salts (c) Acids
2. Acids have _________ taste. (a) sour (b) bitter (c) salty
3. A/an __________ is slippery or soapy when felt and rubbed with the fingers. (a) acid (b) base (c) salt
4. Acids can be classified into _______ based on method of production. (a) 2 (b) 4 (c) 5
5. A base that is soluble in water is also called ___________. (a) alkalis (b) acid (c) concentrated
6. Acid gotten from milk is known as _____________. (a) Acetic acid (b) Lactic acid (c) Citric acid
7. The following are examples of inorganic acids except ____________. (a) Hydrochloric acid (b) Acetic acid (c) Sulphuric acid
8. Mention two uses of the following :
a. Acids : ___________________________________
b. Bases : ___________________________________
Conclusion : At the end of the lesson learners were able to answer the questions correctly.