JAMB and WAEC Chemistry questions

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

1. Question 341· Energy changes· WAEC

   In an exothermic reaction, the energy of the products is

   • Aless than that of the reactants
   • Bgreater than that of the reactants
   • Cequal to that of the reactants
   • Dzero

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2. Question 342· Energy changes· JAMB

   On an energy profile diagram, adding a catalyst

   • Alowers the energy peak (activation energy)
   • Braises the energy of the products
   • Cchanges ΔH
   • Draises the energy peak

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3. Question 343· Energy changes· JAMB

   Breaking chemical bonds is

   • Aan endothermic process
   • Ban exothermic process
   • Cneither endothermic nor exothermic
   • Da nuclear process

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4. Question 344· Energy changes· JAMB

   Which of the following is an endothermic process?

   • Acombustion of petrol
   • Bphotosynthesis
   • Crespiration
   • Dneutralisation

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5. Question 345· Energy changes· JAMB

   The heat of combustion of a substance is the heat released when

   • Aone mole of it burns completely in oxygen
   • Bone gram of it melts
   • Cit dissolves in water
   • Dit is neutralised

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6. Question 346· Energy changes· JAMB

   Entropy is a measure of

   • Aits heat content
   • Bthe disorder of a system
   • Cits temperature
   • Dits pressure

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7. Question 347· Energy changes· WAEC

   Burning butane in a gas cooker is described as exothermic because

   • Ait needs a spark to start
   • Bheat is absorbed from the surroundings
   • Cheat is given out to the surroundings
   • Dthe products are gases

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8. Question 348· Energy changes· JAMB

   A reaction with a negative ΔH is

   • Aexothermic
   • Bendothermic
   • Creversible
   • Dslow

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9. Question 349· Energy changes· WAEC

   Heat released when 2 mol of a substance burns is 1,600 kJ. Find the heat of combustion per mole.

   • A−1,600 kJ/mol
   • B−800 kJ/mol
   • C−3,200 kJ/mol
   • D+800 kJ/mol

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10. Question 350· Energy changes· JAMB

    In an exothermic reaction, the products have

    • Amore energy than the reactants
    • Bless energy than the reactants
    • Cthe same energy as the reactants
    • Dno energy

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11. Question 351· Energy changes· WAEC

    An energy profile diagram where the products are higher in energy than the reactants represents

    • Aa neutral reaction
    • Ban exothermic reaction
    • Can endothermic reaction
    • Da catalysed reaction only

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12. Question 352· Energy changes· WAEC

    A reaction that gives out heat to the surroundings is

    • Aendothermic
    • Bexothermic
    • Creversible
    • Dcatalytic

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13. Question 353· Energy changes· WAEC

    Activation energy is the

    • Aenergy released by a reaction
    • Bminimum energy needed for a reaction to occur
    • Cheat of solution
    • Dbond length

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14. Question 354· Energy changes· JAMB

    In a reaction, 1000 kJ is absorbed in breaking bonds and 1200 kJ is released in forming bonds. Find ΔH.

    • A−2200 kJ
    • B+200 kJ
    • C−200 kJ
    • D+2200 kJ

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15. Question 355· Energy changes· JAMB

    The standard enthalpy of formation of an element in its standard state is

    • Aalways negative
    • B100 kJ/mol
    • Czero
    • Dalways positive

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16. Question 356· Energy changes· JAMB

    For 2H₂(g) + O₂(g) → 2H₂O(l), ΔH = −572 kJ. How much heat is released when 1 g of hydrogen burns? (H = 1)

    • A143 kJ
    • B286 kJ
    • C572 kJ
    • D71.5 kJ

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17. Question 357· Energy changes· JAMB

    The minimum energy that colliding particles must have before they react is the

    • Aenthalpy of reaction
    • Bactivation energy
    • Clattice energy
    • Dionisation energy

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18. Question 358· Energy changes· WAEC

    Which of these processes is endothermic?

    • Aburning of wood
    • Bmelting of ice
    • Crusting of iron
    • Drespiration

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19. Question 359· Energy changes· JAMB

    

    The energy profile shown represents a reaction that is

    • Aat equilibrium
    • Bendothermic
    • Cexothermic
    • Dnot a chemical change

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20. Question 360· Energy changes· WAEC

    The heat change when one mole of water is formed from the neutralisation of an acid by a base is the heat of

    • Acombustion
    • Bneutralisation
    • Cformation
    • Dsolution

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