JAMB and WAEC Chemistry questions: Electrolysis

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

1. Question 21· Electrolysis· JAMB

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

   • Airon
   • Bcopper
   • Czinc
   • Dgraphite

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2. Question 22· 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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3. Question 23· 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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4. Question 24· 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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5. Question 25· 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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6. Question 26· 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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7. Question 27· Electrolysis· WAEC

   During electrolysis, positive ions move towards the

   • Aanode
   • Belectrolyte surface
   • Ccathode
   • Dbattery

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8. Question 28· 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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9. Question 29· Electrolysis· WAEC

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

   • A1
   • B3
   • C2
   • D27

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10. Question 30· 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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11. Question 31· 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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12. Question 32· 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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13. Question 33· 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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14. Question 34· 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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15. Question 35· 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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16. Question 36· 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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17. Question 37· Electrolysis· JAMB

    During electrolysis, positive ions (cations) move towards the

    • Aelectrolyte surface
    • Banode
    • Ccathode
    • Dsalt bridge

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18. Question 38· Electrolysis· JAMB

    In the purification of copper by electrolysis, the impure copper is made the

    • Aanode
    • Bcathode
    • Celectrolyte
    • Dsalt bridge

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19. Question 39· Electrolysis· JAMB

    Sodium is obtained industrially by electrolysing

    • Asodium trioxocarbonate(IV) solution
    • Bbrine
    • Csea water
    • Dmolten sodium chloride

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20. Question 40· Electrolysis· JAMB

    The same charge passes through solutions of AgNO₃ and CuSO₄ in series. If 0.2 mol of silver is deposited, how many moles of copper are deposited?

    • A0.4
    • B0.2
    • C0.1
    • D0.05

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