Chemistry JSS 2 3rd term 2025 Examination

1. Which of the following is a principal composition of crude oil?

2. The search for crude oil and it's exploration is carried out by

3. A substance that cannot be separated by physical means is

4. The following are non-hazardous chemicals except

5. Which principle states that electrons occupy the lowest available energy level?

6. What is the maximum number of electrons that can occupy an S-orbital?

7. What is the electronic configuration of Aluminum?

8. What is the purpose of writing electronic configuration?

9. Which orbital has 10 electrons ?

10. Which principle states that electrons occupy empty orbitals of the same energy level before pairing up?

11. What is the unit of measurement for the quantity of electricity passed during electrolysis?

12. What is the function of an electrolyte in electrolysis?

13. Which electrode is positively charged during electrolysis?

14. What is the process of coating a metal with another metal using electrolysis?

15. Which of the following factors affect the amount of substance deposited during electrolysis?

16. What is the purpose of a salt bridge in an electrochemical cell?

17. What is the percentage of Nitrogen in the Earth's atmosphere?

18. Which compound of Nitrogen is commonly used in the production of explosives?

19. The atomic number of Nitrogen is

20. The chemical formula of Nitrogen (iv) oxide is

Subjective

1. ......... is known as a rechargeable cell.

2. ....... and 3. ......... make up the electrodes in electrolysis

4. Electrons enter into the electrolyte through the..........

5. ....... and 6. ........ are compounds of Nitrogen

7. Ammonia is produced through........... process

8. ....... and 9. ........ are examples of primary cells

10. Write the SPDF configuration of Vanadium with atomic number 23

Essay Answer Only 4 Questions

1a. Define Electrolysis 1b. State and explain 2 factors that affect the preferential discharge of ions during electrolysis 1c. Mention 2 applications of electrolysis

2a. State Hund's rule 2b. Show the orbital diagrams of i. Neon ii. Chlorine 2c. What is orbital/shell?

3a. What is Electrochemical cell? 3b. What is the main function of salt bridge? 3c. Differentiate between primary and secondary cell

4a. Discuss the occurrence of Nitrogen 4b. State 2 physical properties of Nitrogen 4c. Explain the laboratory preparation of Nitrogen

Draw and label Leclanche~ cell 5b. Explain the following i. Electrolyte ii. Battery iii. Electroplating