Activity 1.7 Class 10 Science

This activity explains the Electrolysis of Water which belongs to Chemical Reactions and Equations

Electrolysis of Water

Caution: This activity needs the teacher’s assistance.

 Activity 

1. Take a plastic mug. Drill two holes at its base and fit rubber stoppers in these holes. 

2. Insert carbon electrodes in these rubber stoppers.

3. Connect these electrodes to a 6-volt battery.

4. Fill the mug with water such that the electrodes are immersed. Add a few drops of dilute sulphuric acid to the water.

5. Take two test tubes filled with water and invert them over the two carbon electrodes.

6. Switch on the current and leave the apparatus undisturbed for some time.

7 . You will observe the formation of bubbles at both electrodes. These bubbles displace water in the test tubes.

8. Is the volume of the gas collected the same in both test tubes?

9 . Once the test tubes are filled with the respective gases, remove them carefully.

10. Test these gases one by one by bringing a burning candle close to the mouth of the test tube.

Observation 

Bubbles of gases appear above the electrodes in both test tubes.

When a burning candle is brought near test tube A(containing `H_2` gas), it burns with a popping sound and extinguishes.

When the burning candle is brought near test B(containing `O_2` gas), it burns more brightly.

Conclusion 

The bubbles produced by the passing current are hydrogen and oxygen gases which are formed by the decomposition of water on the passing electric current.

2H₂O(I) →  2H₂(g) + O₂ (g)

The volume of hydrogen collected will be twice the volume of oxygen. 

You can watch the video for this activity 

Activity Video 

Frequently Asked Questions

    1. Which acid has been used in this activity?

    Ans. Sulphuric acid

   2. Name the reaction that takes place in this activity.

     Ans. Decomposition Reaction (Electrolysis)

    3. Name the gases produced in the test tubes.

    Ans. Hydrogen and oxygen

   4. Which gas is present in the test tube in a large amount?

    Ans. Hydrogen

  5. Why sulphuric acid is added to water in activity 1.7 class 10 science?

Ans - Pure water doesn’t conduct electricity more efficiently, when sulphuric acid is added to water, it breaks down into ions (`H^+` and `SO_4^[2-}`) which increases the conductivity of electricity in the water.

Related Topics for you

1. Activity 1.8 Class 10 Science

2. Activity 1.6 Class 10 Science

2. Solution of Chemical Reactions and Equations

3. MCQ Questions of Chapter 1 

4. Extra Questions of Chapter 1