This quiz works best with JavaScript enabled. Home > Cbse > Class 12 > Science > Chemistry Part I > Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics – Quiz 4 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 4 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. Which of the following is a condition for effective collisions to occur? A) Particles should have enough energy. B) Particles should be correctly oriented. C) Both answers are correct. D) None of the above. Show Answer Correct Answer: C) Both answers are correct. 2. The reaction rate is defined as the rate at which the concentration of the reactants ..... with time or the concentration of products ..... with time. A) Increase, decrease. B) Decrease, increase. C) Decrease, decrease. D) Increase, increase. Show Answer Correct Answer: B) Decrease, increase. 3. The order of a reaction may be(choose the best option) A) 0. B) 0, 1. C) 0, 1, 2, 3. D) 0, 1, 2, 3 and even fraction. Show Answer Correct Answer: D) 0, 1, 2, 3 and even fraction. 4. A solution that is in equilibrium with undissolved solute is saturated. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 5. In a reaction if the concentration of reactant A is tripled, the rate of reaction becomes twenty seven times. What is the order of the reaction? A) 3. B) 1. C) 2. D) 0. Show Answer Correct Answer: A) 3. 6. A reaction between an acid and a metal carbonate takes 60 seconds before it iscompleted. Why is the initial rate of the reaction faster than the rate after 50 seconds? A) The temperature of the reaction decreases as it proceeds. B) The concentration of the acid decreases during the reaction. C) The carbon dioxide produced dissolves in the water as the reaction proceeds. D) The particle size of the metal carbonate decreases as the reaction proceeds. Show Answer Correct Answer: B) The concentration of the acid decreases during the reaction. 7. The following is true for reaction mechanism EXCEPT A) Elementary steps must add up to overall balanced equation. B) Molecularity for slow and fast step is 2. C) Proposed mechanism is likely. D) Slow step and fast step dont add up to overall balanced eqn. Show Answer Correct Answer: D) Slow step and fast step dont add up to overall balanced eqn. 8. For a chemical reaction A$\rightarrow$B, it is found that the rate of reaction doubles when the concentration of A is increased four times. The order of reaction is A) Half. B) Zero. C) Two. D) One. Show Answer Correct Answer: A) Half. 9. In a consecutive or series reaction, the rate of formation of B is expressed as A) DB/dt=K1[A]-k2[B]. B) -dB/dt=K1[A]-k2[B]. C) DB/dt=K1[B]-k2[A]. D) DB/dt=K2[B]-k1[A]. Show Answer Correct Answer: A) DB/dt=K1[A]-k2[B]. 10. The conversion of molecules X to Y follows 2nd order kinetics. If concentration of X is increased 3 times, how will it affect the rate of formation of Y A) 6 times. B) 3 times. C) 9 times. D) 8 times. Show Answer Correct Answer: C) 9 times. 11. Which can be determined graphically and at any time A) Slow rate. B) Instantaneous rate. C) Fast rate. D) Average rate. Show Answer Correct Answer: B) Instantaneous rate. 12. On which factor the rate constant of a reaction does not depend upon? a) Temperature b) Activation energy c) Time d) Concentration of reactants and products A) B, D. B) A, B, C. C) A, D. D) C, D. Show Answer Correct Answer: D) C, D. 13. Abigail, Ethan, and Jackson are working on a chemistry project about the decomposition of N$_{2}$O. They found that the half-life of the reaction is 0.204 seconds. Can you help them figure out the rate constant for this first-order decomposition?Hint. t$_{1/2}$ = $\frac{0.693}{k}$ A) 5.40 s$^{-1}$. B) 2.04 s$^{-1}$. C) 3.40 s$^{-1}$. D) 0.204 s$^{-1}$. Show Answer Correct Answer: C) 3.40 s$^{-1}$. 14. Chief Minister, Government of Maharashtra A) Shri Uddhav Thackeray. B) Narendra Modi. C) Devendra Fadnavis. D) Shree Yogi ji. Show Answer Correct Answer: A) Shri Uddhav Thackeray. 15. A reaction's rate: A) Starts faster then slows down. B) Stays constant. C) Starts slower then speeds up. D) None of the above. Show Answer Correct Answer: A) Starts faster then slows down. 16. Describe the role of catalysts in chemical reactions. A) Catalysts only work in specific temperature ranges and have no effect on reaction rates. B) Catalysts are consumed in the reaction and do not affect the overall energy change. C) Catalysts decrease the rate of chemical reactions by increasing activation energy. D) Catalysts increase the rate of chemical reactions by lowering activation energy. Show Answer Correct Answer: D) Catalysts increase the rate of chemical reactions by lowering activation energy. 17. Which of the following is (are) altered when a liquid at its boiling point is converted to a gas at the same temperature?I. The size of the moleculesII. The distance between moleculesIII. The average kinetic energy of the molecules A) I only. B) II only. C) III only. D) I and II. Show Answer Correct Answer: B) II only. 18. Explain the concept of activation energy in chemical reactions. A) Activation energy is the total energy of the reactants. B) Activation energy is the energy required to break chemical bonds. C) Activation energy is the minimum energy required to initiate a chemical reaction. D) Activation energy is the energy released during a reaction. Show Answer Correct Answer: C) Activation energy is the minimum energy required to initiate a chemical reaction. 19. If the intial concentration half life of the reaction is doubled then, the order of reaction is A) 1. B) 3. C) 0. D) 2. Show Answer Correct Answer: C) 0. 20. Which one of the following is a zero order, overall reaction A) K$_{1}$= 10.7 s$^{-1}$. B) K$_{1}$= 1.23 x 10$^{-6}$ M$^{-1}$ s$^{-1}$. C) K$_{1}$= 1.000 M s$^{-1}$. D) K$_{1}$= 5403.2 M$^{1/2}$ s$^{1/2}$. Show Answer Correct Answer: C) K$_{1}$= 1.000 M s$^{-1}$. 21. Rate law for chemical reactions are determined A) By experiment. B) By examining the coefficient in balanced chemical equation. C) From equilibrium constant. D) From the rates of forward and reverse reactions of the system in equilibrium. Show Answer Correct Answer: A) By experiment. 22. Which of the following is true regarding the addition of a catalyst to a reaction? A) The $\Delta$G of a reaction is decreased. B) Energy of activated complex will decrease. C) Rate of reverse reaction decreased. D) The equilibrium favors the products upon catalyst addition. Show Answer Correct Answer: B) Energy of activated complex will decrease. 23. Which of the following is a characteristic of a zero-order reaction? A) Rate increases with temperature. B) Rate depends on concentration. C) Rate decreases with time. D) Rate is constant. Show Answer Correct Answer: D) Rate is constant. 24. A chemical reaction between iron atoms and oxygen molecules can only occur if A) There are effective collisions between the particles. B) The particles are heated. C) There is a catalyst present. D) The atmospheric pressure decreases. Show Answer Correct Answer: A) There are effective collisions between the particles. 25. The role of a catalyst is to change ..... A) Gibbs energy of reaction. B) Activation energy of reaction. C) Enthalpy of reaction. D) Equilibrium constant. Show Answer Correct Answer: B) Activation energy of reaction. 26. A substance 'A' decomposes by a first-order reaction starting initially with [A] = 2.00M and after 200min, [A] becomes 0.15M. For this reaction t1/2 is A) 46.45 min. B) 50.49 min. C) 53.72 min. D) 48.45 min. Show Answer Correct Answer: C) 53.72 min. 27. A student wished to follow the rate of the reaction between calcium carbonate and hydrochloric acid. Which of the following methods would not work? A) Measuring the change in pH of the contents of the flask over time. B) Measuring the change in mass of the contents of the flask over time. C) Measuring the change in colour of the contents of the flask over time. D) Measuring the volume of carbon dioxide gas evolved over time. Show Answer Correct Answer: C) Measuring the change in colour of the contents of the flask over time. 28. Spontaneous reactions always occur rapidly. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: B) False. 29. The number of molecules of the reactants involved in a single stage of the reaction indicates A) The order of the reaction. B) The molecularity of the reaction. C) The rapid step of the reaction mechanism, and. D) The reaction half-life. Show Answer Correct Answer: B) The molecularity of the reaction. 30. The rate of chemical reation double for every 10 degree rise of temperature. If temperature is increased by 50 degree, the rate of reaction will increase by A) 24 times. B) 32 times. C) 64 times. D) 10 times. Show Answer Correct Answer: B) 32 times. 31. The ..... states that atoms, ions, or molecules must collide in order to react. A) Collision theory. B) Activation energy. C) Rate law. D) Transition state. Show Answer Correct Answer: A) Collision theory. 32. An effective collision between reactant particles requires the particles to have the proper A) Charge and mass. B) Charge and orientation. C) Energy and mass. D) Energy and orientation. Show Answer Correct Answer: D) Energy and orientation. 33. Half life for zero order reaction depends upon A) Initial concentration of reactant. B) Initial concentration of product. C) Both 1, 2. D) None of the above. Show Answer Correct Answer: A) Initial concentration of reactant. 34. For a given rate, the unit of rate and the rate constant are the same. A) First order reaction. B) Second order reaction. C) Zero order reaction. D) Third order reaction. Show Answer Correct Answer: C) Zero order reaction. 35. Which of the following is NOT a factor affecting reaction rate? A) Polarity. B) Particle size. C) Temperature. D) Catalysts. Show Answer Correct Answer: A) Polarity. 36. For the elementary reaction M $\rightarrow$ N, the rate of disappearance of M increases by a factor of 8 upon doubling the concentration of M. The order of reaction with respect to M is A) 2. B) 3. C) 4. D) 1. Show Answer Correct Answer: B) 3. 37. True or False:A reaction can be stopped or slowed down by adding an inhibitor. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 38. In a series of reaction, which is the rate determining step A) The slowest reaction. B) The main reaction involving the major reactant. C) The simplest reaction. D) The fastest reaction. Show Answer Correct Answer: A) The slowest reaction. 39. Why do most reactions begin with a fast rate and then get slower and slower? A) The concentration of reactants decreases. B) The catalyst runs out. C) They run out of energy. D) The temperature decreases. Show Answer Correct Answer: A) The concentration of reactants decreases. 40. What is the degree of the following chemical reaction?4Al + 3O$_{2}$ $\rightarrow$ 2Al$_{2}$O$_{3}$ A) 6. B) 4. C) 5. D) 7. Show Answer Correct Answer: D) 7. 41. Among the solids the rate ..... with decrease in size A) Increase. B) Decrease. C) Remains same. D) None. Show Answer Correct Answer: A) Increase. 42. The reaction rate constant may be defined as the rate of the reaction when the concentration of each reactants is ..... A) Unity. B) Infinite. C) Doubled the initial concentration. D) Zero. Show Answer Correct Answer: A) Unity. 43. $Abigail is studying for her chemistry exam. She comes across a problem where for a certain reaction, the rate=k[NO]^2[O_2]. She decides to triple the initial concentration of NO. What would be the effect on the initial rate-$ A) Decreases by a factor of six. B) Noah thinks it would increase by a factor of nine. C) Decreases by a factor of nine. D) William suggests that it might increase by a factor of six. Show Answer Correct Answer: B) Noah thinks it would increase by a factor of nine. 44. The half-life for a zero-order reaction is proportional to: A) Rate constant. B) (Initial concentration)$^{2}$. C) Initial concentration. D) Temperature. Show Answer Correct Answer: C) Initial concentration. 45. What is the molecularity of the reaction 2HI $\rightarrow$ H$_{2}$ + I$_{2}$ A) 1. B) 0. C) 2. D) 4. Show Answer Correct Answer: C) 2. 46. Activation energy can be represented in 2D Potential Energy Surfaces A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 47. Which of the following are true of reaction rates?I. The overall rate law is determined by the fastest step of a reaction II. The presence of a catalyst will increase the number of molecules entering the transition state III. An increase in temperature will increase the rate of a reaction IV. Increasing the concentration of reactants will increase the rate at which products yield A) II+III+IV. B) II + III. C) I+II+III. D) I+IV. Show Answer Correct Answer: B) II + III. 48. A ..... catalyst will increase the rate of the reaction A) Positive. B) Negative. C) Neural. D) None. Show Answer Correct Answer: A) Positive. 49. How does temperature affect the rate of a chemical reaction? A) Lower temperatures always decrease reaction rates. B) Higher temperatures slow down chemical reactions. C) Higher temperatures generally increase the rate of a chemical reaction. D) Temperature has no effect on reaction rates. Show Answer Correct Answer: C) Higher temperatures generally increase the rate of a chemical reaction. 50. WHICH OF THE FOLLLOWING IS NOT A FACTOR AFFECTING RATE OF REACTION A) CONCENTRATION. B) CATALYST. C) PRESSURE. D) TEMPERATURE. Show Answer Correct Answer: C) PRESSURE. 51. What is the effect of increasing temperature on the rate constant? A) Rate constant increases. B) Rate constant remains the same. C) Rate constant decreases. D) Rate constant becomes zero. Show Answer Correct Answer: A) Rate constant increases. 52. The time in which half of the substance has reacted is A) Half life period. B) Full life time. C) Both 1, 2. D) None of the above. Show Answer Correct Answer: A) Half life period. 53. If the concentration of reactant is doubled in a zero-order reaction, the rate will: A) Decrease. B) Double. C) Become four times. D) Remain same. Show Answer Correct Answer: D) Remain same. 54. Do the reactants in an exothermic reaction have a higher or lower energy than the products? A) Higher. B) Lower. C) All the above. D) None of the above. Show Answer Correct Answer: A) Higher. 55. Nuclear reactions follow A) First order kinetics. B) Zero order kinetics. C) Second order kinetics. D) Pseudo first order kinetics. Show Answer Correct Answer: A) First order kinetics. 56. Describe the role of catalysts in altering the reaction rate. A) Catalysts have no effect on the reaction rate. B) Catalysts increase the activation energy barrier for the reaction. C) Catalysts lower the activation energy barrier for the reaction, increasing the rate of reaction without being consumed in the process. D) Catalysts are consumed during the reaction. Show Answer Correct Answer: C) Catalysts lower the activation energy barrier for the reaction, increasing the rate of reaction without being consumed in the process. 57. Any factor that increases the number or force of collisions increases the reaction rate. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 58. The rate expression for the reaction X (g) + 2Y (g) $\rightarrow$ 3Z (g) israte = k[X]$^{0}$ [Y]$^{2}$ By which factor will the rate of reaction increase when the concentrations of X and Y are both increased by a factor of 3? A) 6. B) 27. C) 18. D) 9. Show Answer Correct Answer: D) 9. 59. Reaction between ..... is faster than covalent substances A) Ionic substance. B) Non ionic substance. C) Metallic substance. D) Non metallic substance. Show Answer Correct Answer: A) Ionic substance. 60. The transition state in a reaction is characterized by: A) Maximum potential energy along the reaction coordinate. B) Minimum potential energy along the reaction coordinate. C) Equal potential energy as reactants and products. D) None of the above. Show Answer Correct Answer: A) Maximum potential energy along the reaction coordinate. ← PreviousNext →Related QuizzesScience QuizzesClass 12 QuizzesClass 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 1Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 2Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 3Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 5Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 6Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 7Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 8Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 9 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books