NIOS Class 10 Science and Technology Activity 4.4 Chemical Reactions and Equations

In this activity, we will explore the electrolytic decomposition of water using a simple setup.

NIOS Class 10 Science and Technology Project File

This activity is based on the NIOS class 10 science and technology chapter 4, Chemical Reactions and Equations

Aim of the activity

To observe the decomposition of water into hydrogen and oxygen

Materials Required

    1.  Plastic mug

    2.  Two rubber stoppers

    3. Two graphite electrodes

    4. 6-volt battery

    5. Connecting wires

    6. Two test tubes

    7. Water

    8. Stand

Procedure

We take a clean plastic mug and drill two holes at its bottom. We insert rubber stoppers into the holes and fit graphite electrodes through them. Now we connect these electrodes to the terminals of a 6-volt battery using connecting wires.

We fill the mug with water and place two water-filled test tubes inverted over each electrode. Now we pass electric current through the circuit and observe the changes.

Observation

We observe the bubbles at both electrodes, and water in both test tubes is displaced.

Explanation

When an electric current is passed through water, it splits into hydrogen and oxygen through the process of electrolysis.

During electrolysis, water molecules break down into hydrogen and oxygen.

Hydrogen gas is collected at the cathode, and oxygen gas is collected at the anode.

The volume of hydrogen is twice the volume of oxygen.

      2H₂O  →2H₂ + O₂

Conclusion

 This activity demonstrates that water can be decomposed into hydrogen and oxygen by passing an electric current through it. The ratio of hydrogen and oxygen gases is 2:1.

Frequently Asked Questions

    1. What is the ratio of gases obtained in this activity?

Answer – The ratio is 2:1.

    2. What type of reaction takes place in this activity?

Answer – Electrolytic decomposition (electrolysis)

    3. Which gas is collected at the cathode?

Answer – Hydrogen gas

   4. Why are graphite electrodes used in this activity?

Answer – Graphite is a good conductor of electricity.