Electric conductivity of electrolyte in Electrical Conductivity of Liquids – Class 8 Science Experiment

Chapter Name: Electrical Conductivity of Liquids

Activity Name: Electric conductivity of electrolyte in Electrical Conductivity of Liquids

Activity Description:

In this experiment, the electrical conductivity of different liquids is tested to understand their conductivity properties. Three different containers are taken, each filled with the same amount of distilled water.

Common salt is dissolved in the first container, Copper Sulphate (Mylatuttam) in the second container, and lemon juice in the third container. Using a tester, similar to the one used in Activity 2, the electrical conductivity of each liquid is tested, and observations are recorded in Table 3.

Required Items:

1. Distilled water
2. Common salt
3. Copper Sulphate (Mylatuttam)
4. Lemon juice
5. Tester

Step by Step Procedure:

1. Take three containers and fill each with the same amount of distilled water.
2. Dissolve a small quantity of common salt in the water of the first container.
3. Dissolve Copper Sulphate (Mylatuttam) in the second container and lemon juice in the third container.
4. Using the tester, measure the electrical conductivity of each liquid by placing the tester’s pins into the liquid one at a time.
5. Repeat the conductivity test for each liquid and record the observations in Table 3.
6. After testing each liquid, wash and wipe the pins of the tester dry before testing the next liquid.

Experiment Observations:

1. The observations are recorded in Table 3, and they should show that distilled water does not allow electric current to pass through, while water containing salts or acids (common salt and lemon juice) allows the passage of electric current, turning it into a good conductor of electricity.

Note down your observations in table format:

Precautions:

1. Handle the chemicals with care and follow safety guidelines while performing the experiment.
2. Wash and wipe the tester pins dry after testing each liquid to ensure accurate results.
3. Ensure proper labeling of containers to avoid confusion between the liquids.

Lesson Learnt from Experiment:

The experiment demonstrates that distilled water, in its pure form, is a poor conductor of electricity. However, when it contains dissolved salts or acids, it becomes a good conductor of electricity. This indicates that the presence of ions in the liquid allows the electric current to flow, enabling conductivity.