WAEC Chemistry questions

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

1. Question 181· Kinetic theory of matter and gas laws· WAEC

   A gas at 2 atm and 300 K is heated at constant volume to 450 K. Its new pressure is

   • A1.33 atm
   • B3 atm
   • C4.5 atm
   • D2 atm

   Show answer

   Explanation and discussion

2. Question 182· Kinetic theory of matter and gas laws· WAEC

   The relative rates of diffusion of hydrogen and oxygen are

   • A2 : 1
   • B1 : 4
   • C16 : 1
   • D4 : 1

   Show answer

   Explanation and discussion

3. Question 183· Kinetic theory of matter and gas laws· WAEC

   At s.t.p., one mole of any gas occupies a volume of

   • A24.0 dm³
   • B22.4 dm³
   • C1.0 dm³
   • D11.2 dm³

   Show answer

   Explanation and discussion

4. Question 184· Kinetic theory of matter and gas laws· WAEC

   The particles of a solid

   • Amove freely in all directions
   • Bvibrate about fixed positions
   • Care far apart
   • Dhave no attraction for one another

   Show answer

   Explanation and discussion

5. Question 185· Kinetic theory of matter and gas laws· WAEC

   Why does the pressure of gas in a sealed tin rise when the tin is heated?

   • AIts molecules become larger
   • BIts molecules move faster and hit the walls harder and more often
   • CThe number of molecules increases
   • DIts molecules attract each other more

   Show answer

   Explanation and discussion

6. Question 186· Kinetic theory of matter and gas laws· WAEC

   Which gas diffuses fastest?

   • Achlorine
   • Boxygen
   • Chydrogen
   • Dcarbon dioxide

   Show answer

   Explanation and discussion

7. Question 187· Kinetic theory of matter and gas laws· WAEC

   Which of the following gases diffuses fastest? (H = 1, He = 4, C = 12, O = 16)

   • AO₂
   • BH₂
   • CCO₂
   • DHe

   Show answer

   Explanation and discussion

8. Question 188· Kinetic theory of matter and gas laws· WAEC

   Which assumption of the kinetic theory fails for real gases at high pressure?

   • Athat the volume of the molecules themselves is negligible
   • Bthat molecules move randomly
   • Cthat collisions occur
   • Dthat gases have mass

   Show answer

   Explanation and discussion

9. Question 189· Kinetic theory of matter and gas laws· WAEC

   Which of these gases diffuses fastest at the same temperature? [H = 1, He = 4, N = 14, O = 16]

   • Aoxygen
   • Bammonia
   • Cnitrogen
   • Dhelium

   Show answer

   Explanation and discussion

10. Question 190· Kinetic theory of matter and gas laws· WAEC

    A gas has a volume of 250 cm³ at 27 °C. Find its volume at 87 °C at constant pressure.

    • A250 cm³
    • B805 cm³
    • C208 cm³
    • D300 cm³

    Show answer

    Explanation and discussion

11. Question 191· Kinetic theory of matter and gas laws· WAEC

    Diffusion is fastest in

    • Asolids
    • Bliquids
    • Cgases
    • Dmetals

    Show answer

    Explanation and discussion

12. Question 192· Kinetic theory of matter and gas laws· WAEC

    Gas X diffuses four times as fast as oxygen under the same conditions. Find the relative molecular mass of X. [O = 16]

    • A16
    • B8
    • C128
    • D2

    Show answer

    Explanation and discussion

13. Question 193· Kinetic theory of matter and gas laws· WAEC

    According to the kinetic theory, gas pressure is caused by

    • Aattraction between molecules
    • Bcollisions of molecules with the container walls
    • Cthe weight of the gas only
    • Dheat alone

    Show answer

    Explanation and discussion

14. Question 194· Kinetic theory of matter and gas laws· WAEC

    According to the kinetic theory, the particles of a gas

    • Aare at rest
    • Bare fixed in position
    • Cattract each other strongly
    • Dmove randomly at high speed

    Show answer

    Explanation and discussion

15. Question 195· Kinetic theory of matter and gas laws· WAEC

    A fixed mass of gas occupies 600 cm³ at 300 K and 1 atm. Find its volume at 400 K and 2 atm.

    • A900 cm³
    • B400 cm³
    • C225 cm³
    • D1600 cm³

    Show answer

    Explanation and discussion

16. Question 196· Kinetic theory of matter and gas laws· WAEC

    The particles in a solid

    • Amove freely in all directions
    • Bvibrate about fixed positions
    • Care far apart
    • Dhave no forces between them

    Show answer

    Explanation and discussion

17. Question 197· Metals and their compounds· WAEC

    An alloy of copper and zinc is

    • Abronze
    • Bbrass
    • Csteel
    • Dsolder

    Show answer

    Explanation and discussion

18. Question 198· Metals and their compounds· WAEC

    Which of these properties is typical of metals?

    • Athey are poor conductors of heat
    • Bthey are brittle
    • Cthey have low melting points
    • Dthey conduct electricity

    Show answer

    Explanation and discussion

19. Question 199· Metals and their compounds· WAEC

    Galvanised iron sheets used for roofing are coated with

    • Azinc
    • Btin
    • Ccopper
    • Dchromium

    Show answer

    Explanation and discussion

20. Question 200· Metals and their compounds· WAEC

    Limestone in the blast furnace removes

    • Aoxygen
    • Bcarbon
    • Csilica impurities as slag
    • Diron

    Show answer

    Explanation and discussion