JAMB and WAEC Chemistry questions

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

1. Question 61· Air· WAEC

   The gas in the air used for filling the space above food in packets to keep it fresh is

   • Ahydrogen
   • Boxygen
   • Cnitrogen
   • Dchlorine

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2. Question 62· Air· JAMB

   Air is regarded as a mixture because

   • Aits components can be separated by physical means
   • Bit contains oxygen
   • Cit is colourless
   • Dit supports burning

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3. Question 63· Air· WAEC

   The gas in the air that causes iron to rust together with water is

   • Anitrogen
   • Boxygen
   • Cargon
   • Dneon

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4. Question 64· Air· WAEC

   Nitrogen is obtained industrially by

   • Aburning coal
   • Bheating ammonium nitrite
   • Celectrolysis of water
   • Dfractional distillation of liquid air

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5. Question 65· Air· JAMB

   The percentage of argon in dry air is about

   • A78%
   • B21%
   • C0.9%
   • D0.03%

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6. Question 66· Air· WAEC

   The percentage of oxygen in air can be found by passing a measured volume of air over

   • Aheated copper
   • Bcold water
   • Csodium chloride
   • Dsilica gel

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7. Question 67· Air· WAEC

   Water vapour in air can be detected by

   • Alime water turning milky
   • Banhydrous cobalt(II) chloride paper turning pink
   • Ca glowing splint relighting
   • Dlitmus turning red

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8. Question 68· Air· JAMB

   Which gas in the air do green plants use for photosynthesis?

   • Aargon
   • Bnitrogen
   • Ccarbon(IV) oxide
   • Dneon

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9. Question 69· Air· WAEC

   The most abundant gas in air is

   • Aoxygen
   • Bcarbon dioxide
   • Cnitrogen
   • Dargon

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10. Question 70· Air· JAMB

    A candle burning in a closed jar soon goes out because

    • Athe oxygen in the jar is used up
    • Bthe jar becomes too hot
    • Cnitrogen is produced
    • Dthe wax runs out

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11. Question 71· Air· JAMB

    The approximate percentage by volume of carbon(IV) oxide in clean air is

    • A1%
    • B21%
    • C0.04%
    • D78%

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12. Question 72· Air· JAMB

    Oxygen and nitrogen are obtained industrially from air by

    • Afractional distillation of liquid air
    • Belectrolysis of water
    • Cheating limestone
    • Dburning charcoal

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13. Question 73· Air· WAEC

    Air is passed over heated copper turnings and the copper turns black. This is because

    • Anitrogen combines with the copper
    • Boxygen in the air forms copper(II) oxide
    • Cthe copper absorbs water vapour
    • Dcarbon(IV) oxide is deposited on it

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14. Question 74· Air· JAMB

    Which gas turns lime water milky but has NO effect on acidified potassium heptaoxodichromate(VI)?

    • Aammonia
    • Bsulphur(IV) oxide
    • Ccarbon(IV) oxide
    • Dhydrogen sulphide

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15. Question 75· Air· JAMB

    Incomplete combustion of fuels in a limited supply of air produces

    • Aoxygen
    • Bcarbon(II) oxide
    • Cnitrogen
    • Dozone

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16. Question 76· Air· JAMB

    In the fractional distillation of liquid air, the first gas to boil off is nitrogen because it has the

    • Amost reactivity
    • Bhighest boiling point
    • Cgreatest density
    • Dlowest boiling point

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17. Question 77· Air· WAEC

    Approximately what percentage of dry air by volume is oxygen?

    • A21%
    • B78%
    • C1%
    • D0.03%

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18. Question 78· Air· WAEC

    Which noble gas is used in advertising signs because it glows red when electricity passes through it?

    • Aneon
    • Bhelium
    • Cargon
    • Dxenon

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19. Question 79· Air· JAMB

    Argon makes up about what percentage of the air by volume?

    • A78%
    • B21%
    • C0.04%
    • D1%

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20. Question 80· Air· WAEC

    The noble gas used in advertising signs because it glows red is

    • Akrypton
    • Bargon
    • Chelium
    • Dneon

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