Identifying Acids and Bases- Grade 5

• Most substances are both acids and bases in nature.

• However, we cannot taste each and every substance to tell whether it is an acid or a base.

• In order to taste whether it’s an acid or base we use a litmus paper to find out whether a substance is acidic or basic in nature.

• The litmus paper is known as an indicator. Indicators change their colour when they are dipped in a solution containing an acidic or a basic substance. Lemon juice turns the blue litmus paper red. This means that lemon juice is acidic

• Wood ash solution turns red litmus paper blue. This means that the wood as solution is a base.

Common substances used as acids and bases

Blue litmus paper turns red when dipped into:

1. Lemon juice

2. Grape juice

3. Orange juice

4. Sour milk

 Therefore, soap, antacid tablets, baking soda and wood ash are bases.

Physical properties of acids and bases Acids

1. They have sour taste

2. They turn blue litmus paper red.

Bases

1. Have bitter taste

2. They are slippery when touched

3. Turn red litmus paper blue

Uses of acids and bases

Acids

1. Acids in fruits such as lemon and orange is used to enhance taste in drinks and to flavor

2. Lemon acid is used in some cultures to make milk sour

3. Vinegar contains acid that is used for cooking purposes and it is also used to give salads a delicious taste.

4. Vehicles have batteries that have an acid which is used to produce electricity.

Bases

1. There are various items used on a daily basis that contain bases. They include:

2. Baking powder is used to bake bread, burns and doughnuts Antacid tablets are used to relieve heartburn.

3. Soap is used for bathing. We use detergents to wash our clothes We clean our teeth using toothpaste.