Litmus paper test on substances in ACIDS AND BASES – Class 7 Science Experiment

Chapter Name: ACIDS AND BASES

Activity Name: Litmus paper test on substances in ACIDS AND BASES

Activity Description:

In this experiment, we will test various salt substances using red litmus and blue litmus papers. The purpose is to determine whether the salts are acidic, basic, or neutral based on their effects on the litmus papers.

Required Items:

1. Red litmus paper
2. Blue litmus paper
3. Copper Sulphate (CuSO4)
4. Common Salt (Sodium Chloride – NaCl)
5. Sodium Carbonate (Na2CO3)

Step by Step Procedure:

1. Prepare a table to record observations.

Experiment Observations:

Salt Substance	Effect on Blue Litmus Paper	Effect on Red Litmus Paper
Copper Sulphate	Turns red	No change
Common Salt	No change	No change
Sodium Carbonate	No change	Turns blue

Precautions:

1. Handle the salt substances with care, avoiding direct contact with the skin or eyes.
2. Use clean and dry litmus papers for accurate observations.
3. Dispose of the used litmus papers and salt substances properly according to safety guidelines.

Lesson Learnt from Experiment:

Through this experiment, we will observe how different salt substances interact with blue and red litmus papers. This will help us identify whether the salts are acidic, basic, or neutral based on their effects on the litmus papers.

The experiment reinforces the concept of using litmus paper as an indicator to differentiate between acidic, basic, and neutral substances.