Chemical effects of electric current Worksheet-6

Chemical effects of electric current Worksheet-6

1. Classify the following liquids into conductors and insulators :

Lemon juice, distilled water, tap water, milk.

2. What are electrodes?

3. What is an electrolyte?

4. What happens when an electric current is passed through a conducting solution?

5. Define electroplating.

6. Which is the most common application of chemical effect of current?

7. Apart from chemical effect, which other effect electric current produce?

8. Is air an insulator or conductor of electricity?

9. Name the process of covering one metal with another metal with help of electricity.

10. Name one non-metal which a good conductor of electricity.

11. What is electrolysis?

12. In what proportion the two products from electrolysis of water are obtained?

13. What is CFL?

14. What is an electric pen?

15. Deposits can be seen in containers used for storing water. Explain why these deposits occur.

16. Why is chromium used for electroplating?

17. Why the iron cans are electroplated with tin?

18. Why should you not do the experiments on electricity by using electric supply from mains ?

19. If the ends of the wire of tester are touched for a long time, what will happen?

20. What is the disadvantage of electroplating done in the factories?

Answer:

1. Conductors : Lemon juice, tap water

Insulators : distilled water, milk.

2. Electrodes are the terminals through which current is passed into a liquid.

3. An electrolyte is a liquid which is a good conductor of current.

4. A chemical reaction takes place when electric current is passed through a conducting solution.

5. Electroplating is the process of depositing a layer of any desired metal on another metallic object by means of electricity.

6. Electroplating

7. Electric current can produce magnetic effect also.

8. Air is an insulator of electricity.

9. Electroplating

10. Graphite

11. Electrolysis is the breaking up of a compound from its solution on passing electric current through the electrolyte.

12. By volume of hydrogen gas is twice the volume of oxygen gas.

13. Compact Fluorescent Lamps

14. It is a device for writing on the surface with special compounds and material using the electrical property of ions.

15. In containers, water evaporates slowly. The salts separate out and deposit on the sides of the container.

16. Chromium is used for electroplating because it has a shiny appearance, does not corrode and is scratch resistant.

17. Tin is less reactive than iron. Thus food, stored in iron cans, is prevented from being spoilt by the iron by electroplating it by tin.

18. We should not do the experiments on electricity by using electric supply from the mains because there is large amount of current and the person using it can get electrocuted.

19. If the ends of the wire of tester are touched for a long time, the cells will be finished very soon.

20. The disposal of the used conducting solution is hazardous and can cause environmental pollution. There are specific disposal guidelines for environmental protection.