JAMB Chemistry questions

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

1. Question 341· Oxidation and reduction· JAMB

   The oxidation number of manganese in KMnO₄ is:

   • A+2
   • B+4
   • C+6
   • D+7

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2. Question 342· Oxidation and reduction· JAMB

   Find the oxidation number of chlorine in NaClO₃.

   • A−1
   • B+3
   • C+7
   • D+5

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3. Question 343· Oxidation and reduction· JAMB

   In terms of oxygen, reduction is the

   • Aaddition of oxygen to a substance
   • Bremoval of oxygen from a substance
   • Caddition of electrons only
   • Dloss of hydrogen

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4. Question 344· Oxidation and reduction· JAMB

   In the reaction CuO + H₂ → Cu + H₂O, the reducing agent is

   • ACu
   • BCuO
   • CH₂
   • DH₂O

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5. Question 345· Oxidation and reduction· JAMB

   Find the oxidation number of nitrogen in HNO₃.

   • A+5
   • B+3
   • C+4
   • D−3

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6. Question 346· Oxidation and reduction· JAMB

   Hydrogen peroxide can act as

   • Aonly an acid
   • Bboth an oxidising agent and a reducing agent
   • Conly a base
   • Dan inert substance

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7. Question 347· Oxidation and reduction· JAMB

   Find the oxidation number of sulphur in H₂SO₄.

   • A+2
   • B+4
   • C+6
   • D−2

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8. Question 348· Oxidation and reduction· JAMB

   In the reaction H₂S + Cl₂ → 2HCl + S, hydrogen sulphide acts as

   • Aa reducing agent
   • Ban oxidising agent
   • Ca catalyst
   • Dan acid only

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9. Question 349· Oxidation and reduction· JAMB

   Which of the following is a redox reaction?

   • AAgNO₃ + NaCl → AgCl + NaNO₃
   • BNaOH + HCl → NaCl + H₂O
   • CZn + 2HCl → ZnCl₂ + H₂
   • DCaCO₃ → CaO + CO₂

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10. Question 350· Oxidation and reduction· JAMB

    Find the oxidation number of iron in Fe₂O₃.

    • A+6
    • B+2
    • C+3
    • D−3

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11. Question 351· Oxidation and reduction· JAMB

    Iron pipes buried in the ground are protected by attaching blocks of magnesium. This is called

    • Atinning
    • Bgalvanising
    • Celectroplating
    • Dsacrificial protection

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12. Question 352· Oxidation and reduction· JAMB

    In 2Na + Cl₂ → 2NaCl, sodium is

    • Aneutralised
    • Breduced
    • Coxidised
    • Dhydrolysed

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13. Question 353· Oxidation and reduction· JAMB

    Find the oxidation number of nitrogen in the ammonium ion, NH₄⁺.

    • A+3
    • B−3
    • C+5
    • D+4

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14. Question 354· Oxidation and reduction· JAMB

    In the reaction 2Mg + O₂ → 2MgO, magnesium is

    • Areduced
    • Boxidised
    • Ca catalyst
    • Dneutralised

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15. Question 355· Oxidation and reduction· JAMB

    Find the oxidation number of manganese in MnO₂.

    • A+6
    • B+2
    • C+7
    • D+4

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16. Question 356· Oxidation and reduction· JAMB

    In the reaction Zn + Cu²⁺ → Zn²⁺ + Cu, zinc is:

    • Areduced
    • Bunchanged
    • Cthe oxidising agent
    • Doxidised

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17. Question 357· Rates of chemical reaction· JAMB

    Sunlight speeds up the reaction between hydrogen and chlorine because it

    • Asupplies energy to break Cl–Cl bonds
    • Bcools the mixture
    • Cis a reactant
    • Dremoves the product

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18. Question 358· Rates of chemical reaction· JAMB

    Which of the following reactions is greatly speeded up by light?

    • Azinc and dilute acid
    • Bhydrogen and chlorine forming hydrogen chloride
    • Cneutralisation of an acid by an alkali
    • Ddecomposition of limestone

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19. Question 359· Rates of chemical reaction· JAMB

    The rate of a reaction is greatest at the start and falls with time because

    • Amore products slow the reaction
    • Bthe catalyst is used up
    • Cthe temperature always falls
    • Dthe concentration of the reactants decreases

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20. Question 360· Rates of chemical reaction· JAMB

    

    In the energy profile shown, the energy labelled X is the

    • Aactivation energy
    • Benthalpy change of the reaction
    • Cenergy of the products
    • Dbond energy of the products

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