Quiz  /  Heat of Reaction Class 9 MCQ Questions With Answers

  • 1. 
    Which one of the following reaction(s) are (is) exothermic?

  • combustion of gases
  • Freezing of water
  • Melting of salt
  • Both A & B

  • 2. 
    Neutralisation reactions

  • endothermic
  • exothermic

  • 3. 
    Check only the FALCE statements:

  • The heat change at the end of a chemical reaction under constant pressure is called the bond energy.
  • Melting of salt is an exothermic process.
  • Freezing is an endothermic process.
  • All of above

  • 4. 
    What is the formula for calculating heat?

  • H = mc θ\thetaθ
  • H = ΔH x n
  • H = ΔH x mass
  • products - reactants

  • 5. 
    Check only the TRUE statements:

  • In endothermic reaction, the total energy of products is bigger than that of reactants.
  • Melting is an endothermic process.
  • Sublimation is the physical process when solid turns to gas.
  • All of above

  • 6. 
    Convert 42 kJ into joules

  • 0.042 J
  • 4200 J
  • 42000 J
  • 420 J

  • 7. 
    The branch of chemistry that focuses on the study of heat released, or absorbed by chemical or physical processes is called ……………………….

  • thermochemistry
  • thermodynamics
  • thermo chemistry
  • None of these

  • 8. 
    In an experiment, 2 g of magnesium powder are added to 50 cm3 of 0.2 mol dm–3 zinc sulphate solution. The temperature of the mixture increases by 12°C. What is the heat of displacement in this experiment?[Spesific heat capacity of a solution = 4.2 Jg–1 °C–1; Relative atomic mass of Mg = 24]

  • – 50.4 kJ mol-1
  • – 100 kJ mol-1
  • – 252 kJ mol-1
  • – 340 kJ mol-1

  • 9. 
    Which one of the following reactions are endothermic?

  • Fe(s)→Fe(l)
  • 2C+2H2+20kcal/mol → C2H
  • Ba(OH)2+CO2 → BaCO3+H2O+heat
  • Both A & B

  • 10. 
    Which of the following regarding an endothermic reaction is correct?

  • Chemical energy is transformed to heat energy
  • The temperature of the surroundings rises
  • Heat is released
  • The energy content of the product is higher than the energy content of the reactants

  • 11. 
    The ______________is required to break the bonds of the reactants.

  • Carbonic energy
  • Activation energy
  • Plutonic energy
  • Energi Gaib

  • 12. 
    What sort of reaction happens when an acid and an alkali are mixed?

  • Neutralisation
  • Combination
  • Acidifying
  • Displacement

  • 13. 
    A change in matter in which heat is absorbed is ..... process

  • Endothermic
  • Exothermic
  • Absorbed
  • Gained

  • 14. 
    In an exothermic reaction, heat is ...

  • taken in
  • given out

  • 15. 
    The following graph shows two different reaction pathways for the same overall reaction at the same temperature. Which pathway is slower and why?

  • Red, because the activation energy is larger
  • Blue, because the activation energy is lower
  • both reaction progress at the same rate

  • 16. 
    In a chemical reaction, energy is used to :

  • cause a change of state
  • overcome intermolecular forces
  • break or form bonds within molecules
  • All of above

  • 17. 
    Compound P is dissolved in water in a test tube. It is noted that the wall of the test tube becomes cold. Which of the following is most probably compound P?

  • Sulphuric acid
  • Ammonia
  • Hydrochloride Acid
  • Ammonium chloride
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