JAMB and WAEC Chemistry questions

800 questions with answers and explanations. Tap an option to check yourself.

1. Question 481· Metals and their compounds· WAEC

   Aluminium is extracted by

   • Adisplacement by copper
   • Breduction with carbon
   • Cheating alone
   • Delectrolysis of molten alumina in cryolite

   Show answer

   Answer: D. electrolysis of molten alumina in cryolite

   Explanation and discussion

2. Question 482· Metals and their compounds· JAMB

   Which metal reacts violently with cold water?

   • Apotassium
   • Bcopper
   • Ciron
   • Dzinc

   Show answer

   Answer: A. potassium

   Explanation and discussion

3. Question 483· Metals and their compounds· JAMB

   Copper is widely used for electrical wiring because it

   • Ais a good conductor and can be drawn into wires
   • Bis cheap and brittle
   • Cis magnetic
   • Ddoes not conduct heat

   Show answer

   Answer: A. is a good conductor and can be drawn into wires

   Explanation and discussion

4. Question 484· Metals and their compounds· WAEC

   Aluminium is extracted from

   • Ahaematite
   • Bcassiterite
   • Cgalena
   • Dbauxite

   Show answer

   Answer: D. bauxite

   Explanation and discussion

5. Question 485· Metals and their compounds· WAEC

   Aluminium does not corrode easily because it

   • Ais covered by a thin protective oxide layer
   • Bis unreactive
   • Chas a low density
   • Dis a non-metal

   Show answer

   Answer: A. is covered by a thin protective oxide layer

   Explanation and discussion

6. Question 486· Metals and their compounds· WAEC

   The rusting of iron requires both

   • Aheat and light
   • Boxygen and nitrogen
   • Cwater and carbon dioxide
   • Dwater and oxygen

   Show answer

   Answer: D. water and oxygen

   Explanation and discussion

7. Question 487· Metals and their compounds· WAEC

   Copper is used for electrical wiring because it

   • Ais very hard
   • Bis a good conductor and can be drawn into wires
   • Cdoes not conduct heat
   • Dis magnetic

   Show answer

   Answer: B. is a good conductor and can be drawn into wires

   Explanation and discussion

8. Question 488· Non-metals and their compounds· WAEC

   Which of these gases can be collected over water?

   • Ahydrogen chloride
   • Bammonia
   • Chydrogen
   • Dsulphur(IV) oxide

   Show answer

   Answer: C. hydrogen

   Explanation and discussion

9. Question 489· Non-metals and their compounds· JAMB

   Silicon is used mainly in

   • Afertilisers
   • Bsemiconductor chips
   • Cbleaching
   • Dfuels

   Show answer

   Answer: B. semiconductor chips

   Explanation and discussion

10. Question 490· Non-metals and their compounds· JAMB

    Chlorine gas is identified by its:

    • Abrown colour
    • Brotten-egg smell
    • Cgreenish-yellow colour and bleaching action
    • Dability to relight a glowing splint

    Show answer

    Answer: C. greenish-yellow colour and bleaching action

    Explanation and discussion

11. Question 491· Non-metals and their compounds· JAMB

    The allotropes of carbon include:

    • Aozone and oxygen
    • Bred and white phosphorus
    • Crhombic and monoclinic sulphur
    • Dgraphite and diamond

    Show answer

    Answer: D. graphite and diamond

    Explanation and discussion

12. Question 492· Non-metals and their compounds· WAEC

    Moist chlorine bleaches litmus paper because it forms

    • Ahydrochloric acid only
    • Bchlorine dioxide
    • Csulphuric acid
    • Dhypochlorous acid (HOCl)

    Show answer

    Answer: D. hypochlorous acid (HOCl)

    Explanation and discussion

13. Question 493· Non-metals and their compounds· WAEC

    Carbon(IV) oxide is used in fire extinguishers because it

    • Ais denser than air and does not support burning
    • Bis lighter than air
    • Cis poisonous
    • Dburns slowly

    Show answer

    Answer: A. is denser than air and does not support burning

    Explanation and discussion

14. Question 494· Non-metals and their compounds· JAMB

    Ammonia gas is collected by upward delivery because it is

    • Apoisonous
    • Bdenser than air
    • Cinsoluble in water
    • Dless dense than air and very soluble in water

    Show answer

    Answer: D. less dense than air and very soluble in water

    Explanation and discussion

15. Question 495· Non-metals and their compounds· WAEC

    A gas that turns moist red litmus blue is

    • Asulphur dioxide
    • Bchlorine
    • Chydrogen chloride
    • Dammonia

    Show answer

    Answer: D. ammonia

    Explanation and discussion

16. Question 496· Non-metals and their compounds· JAMB

    The two crystalline allotropes of sulphur are

    • Aplastic and amorphous
    • Bgraphite and diamond
    • Cred and white
    • Drhombic and monoclinic

    Show answer

    Answer: D. rhombic and monoclinic

    Explanation and discussion

17. Question 497· Non-metals and their compounds· WAEC

    Which of these non-metals is a liquid at room temperature?

    • Abromine
    • Bchlorine
    • Ciodine
    • Dsulphur

    Show answer

    Answer: A. bromine

    Explanation and discussion

18. Question 498· Non-metals and their compounds· JAMB

    Which halogen is a liquid at room temperature?

    • Afluorine
    • Bchlorine
    • Ciodine
    • Dbromine

    Show answer

    Answer: D. bromine

    Explanation and discussion

19. Question 499· Non-metals and their compounds· WAEC

    Which gas forms dense white fumes when it meets hydrogen chloride gas?

    • AOxygen
    • BAmmonia
    • CNitrogen
    • DCarbon dioxide

    Show answer

    Answer: B. Ammonia

    Explanation and discussion

20. Question 500· Non-metals and their compounds· WAEC

    Sulphur(IV) oxide bleaches coloured materials by

    • Aoxidation
    • Breduction
    • Cdehydration
    • Dneutralisation

    Show answer

    Answer: B. reduction

    Explanation and discussion