JAMB and WAEC Chemistry questions

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

1. Question 301· Electrolysis· WAEC

   The mass of copper deposited by 0.2 mol of electrons (Cu = 64, Cu²⁺) is

   • A64 g
   • B12.8 g
   • C3.2 g
   • D6.4 g

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2. Question 302· Electrolysis· WAEC

   The positive electrode in electrolysis is the

   • Aanode
   • Bcathode
   • Celectrolyte
   • Dvoltameter

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3. Question 303· Electrolysis· JAMB

   When dilute tetraoxosulphate(VI) acid is electrolysed with platinum electrodes, the products are

   • Ahydrogen at the cathode and oxygen at the anode
   • Boxygen at the cathode and hydrogen at the anode
   • Csulphur at the anode
   • Dsulphur(IV) oxide at the cathode

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4. Question 304· Electrolysis· WAEC

   In the electrolysis of acidified water, the gas given off at the anode is

   • Ahydrogen
   • Bcarbon dioxide
   • Cchlorine
   • Doxygen

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5. Question 305· Electrolysis· JAMB

   Which of the following is commonly used as an inert electrode?

   • Airon
   • Bcopper
   • Czinc
   • Dgraphite

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6. Question 306· Electrolysis· WAEC

   What mass of silver is deposited when 9650 C pass through silver trioxonitrate(V) solution? [Ag = 108, F = 96 500 C]

   • A10.8 g
   • B108 g
   • C1.08 g
   • D21.6 g

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7. Question 307· Electrolysis· JAMB

   How many moles of silver are deposited by 9650 C of electricity from Ag⁺ ions? (F = 96 500 C/mol)

   • A0.1 mol
   • B1 mol
   • C0.01 mol
   • D0.05 mol

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8. Question 308· Electrolysis· JAMB

   The electrolysis of brine produces

   • Ahydrogen and oxygen only
   • Bsodium and oxygen
   • Cchlorine and sodium metal only
   • Dchlorine, hydrogen and sodium hydroxide

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9. Question 309· Electrolysis· WAEC

   During the electrolysis of copper(II) tetraoxosulphate(VI) solution with copper electrodes, the anode

   • Adissolves and becomes thinner
   • Bgains mass
   • Cgives off oxygen
   • Dgives off hydrogen

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10. Question 310· Electrolysis· JAMB

    In the electrolysis of acidified water, the ratio of the volume of hydrogen to oxygen produced is

    • A2 : 1
    • B1 : 2
    • C1 : 1
    • D4 : 1

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11. Question 311· Electrolysis· WAEC

    During electrolysis, positive ions move towards the

    • Aanode
    • Belectrolyte surface
    • Ccathode
    • Dbattery

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12. Question 312· Electrolysis· WAEC

    A substance that conducts electricity when molten or in solution and is decomposed by it is

    • Aa metal
    • Ba non-electrolyte
    • Can electrolyte
    • Dan insulator

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13. Question 313· Electrolysis· WAEC

    How many faradays are needed to deposit one mole of aluminium from Al³⁺ ions?

    • A1
    • B3
    • C2
    • D27

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14. Question 314· Electrolysis· JAMB

    In the electrolysis of molten lead(II) bromide, the products are

    • Alead at both electrodes
    • Bbromine at the cathode and lead at the anode
    • Chydrogen and oxygen
    • Dlead at the cathode and bromine at the anode

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15. Question 315· Electrolysis· WAEC

    The quantity of electricity passed when 2 A flows for 965 s is

    • A965 C
    • B1,930 C
    • C482.5 C
    • D3,860 C

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16. Question 316· Electrolysis· JAMB

    A current of 2 A flows for 965 s through a solution of a divalent metal salt. The amount of metal deposited is: (F = 96 500 C/mol)

    • A0.005 mol
    • B0.02 mol
    • C0.01 mol
    • D0.1 mol

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17. Question 317· Electrolysis· JAMB

    In the electrolysis of dilute sodium chloride solution with inert electrodes, the gas mainly given off at the anode is

    • Asodium
    • Bchlorine
    • Chydrogen
    • Doxygen

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18. Question 318· Electrolysis· JAMB

    What quantity of electricity deposits 6.4 g of copper from Cu²⁺ ions? [Cu = 64, F = 96,500 C]

    • A19,300 C
    • B9,650 C
    • C96,500 C
    • D38,600 C

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19. Question 319· Electrolysis· WAEC

    Which of these conducts electricity by the movement of ions?

    • Aa copper wire
    • Bmolten lead(II) bromide
    • Ca graphite rod
    • Dsolid sodium chloride

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20. Question 320· Electrolysis· WAEC

    In electrolysis, the cathode is the electrode

    • Aconnected to the positive terminal
    • Bwhere oxidation occurs
    • Cconnected to the negative terminal, where reduction occurs
    • Dthat always dissolves

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