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 7 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 7 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. In a reversible reaction, the activation energies of the forward and the backward reaction are equal. In such reactions A) $\Delta S=0$. B) $\Delta H\ne0, \Delta S\ne0$. C) Order is zero. D) $\Delta H=0$. Show Answer Correct Answer: D) $\Delta H=0$. 2. Olivia is studying a chemical reaction where 2 molecules of substance A react to form 3 molecules of substance B:2A $\rightarrow$ $\\frac{\Delta\left[B\right]}{\Delta t}$ A) $-2[A])/3t$. B) $\frac{\Delta\left[A\right]}{\Delta t}$. C) $\frac{-\Delta\left[A\right]}{\Delta t}$. D) $\frac{-3\Delta\left[A\right]}{2\Delta t}$. Show Answer Correct Answer: D) $\frac{-3\Delta\left[A\right]}{2\Delta t}$. 3. What is half life for first order reaction? A) T$_{1/2 }$= 0.693/k. B) T$_{1/2 }$= 0.683/R. C) T$_{1/2 }$= 1/ k. D) None of the above. Show Answer Correct Answer: A) T$_{1/2 }$= 0.693/k. 4. Describe a first-order reaction with an example. A) The reaction of sodium bicarbonate (NaHCO3) with acetic acid (CH3COOH) is first-order. B) The combustion of methane (CH4) in oxygen (O2) is a first-order reaction. C) The synthesis of ammonia (NH3) from nitrogen (N2) and hydrogen (H2) is a first-order reaction. D) An example of a first-order reaction is the decomposition of hydrogen peroxide (H2O2) into water (H2O) and oxygen (O2). Show Answer Correct Answer: D) An example of a first-order reaction is the decomposition of hydrogen peroxide (H2O2) into water (H2O) and oxygen (O2). 5. A given sample of milk turns sour at room temperature (27$^{0}$C) in 5hours. In a refrigerator at-3$^{0}$C, it can be stored 10 times longer. The energy of activation for the souring of milk is: A) 2.303 $\times$. B) 2.303 $\times$. C) 2.303 $\times$. D) 2.303 $\times$. Show Answer Correct Answer: A) 2.303 $\times$. 6. When it is necessary and required to obtain the value of an intercept form the graph of a straight-line equation, one may use two different available approaches. Each approach however, requires knowledge of the slope of the graph. Slope or intercepts A) FALSE. B) TRUE. C) All the above. D) None of the above. Show Answer Correct Answer: A) FALSE. 7. With the increase in temperature, the average kinetic energy of the molecules increases, leading to a decrease in number of collisions per unit time. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: B) False. 8. If the rate of the reaction is equal to the rate constant, then the order of the reaction is A) 3. B) 0. C) 2. D) 1. Show Answer Correct Answer: B) 0. 9. On a maxwell-Boltzmann distribution curve, what would be a suitable x-axis label? A) Kinetic Energy. B) Potential Energy. C) Activation Energy. D) Temperature. Show Answer Correct Answer: A) Kinetic Energy. 10. A liquid medicine having an initial drug concentration of 1000 mg/ml undergoes zero-order kinetics with a rate constant of 100 mg/ml per day. How long it would take before the product is completely degraded. A) 100 days. B) 10 hours. C) 10 days. D) 1000 hours. Show Answer Correct Answer: C) 10 days. 11. What is the sign of $\Delta$H for all endothermic reactions? A) Positive. B) Negative. C) All the above. D) None of the above. Show Answer Correct Answer: A) Positive. 12. Which of the following best describes the role of a catalyst in a chemical reaction? A) It increases the activation energy, thereby increasing the reaction rate. B) It provides an alternative reaction pathway with a lower activation energy. C) It increases the equilibrium constant of the reaction. D) It gets consumed in the reaction and does not regenerate. Show Answer Correct Answer: B) It provides an alternative reaction pathway with a lower activation energy. 13. If C$_{0}$ is the initialconcentration then the half life period (t$_{1/2}$) for the third order kinetics is ..... A) T$_{1/2}$ = 3/2kC$_{0}$$^{2}$. B) T$_{1/2}$ = 1/kC$_{0}$. C) T$_{1/2}$ = 3k/2C$_{0}$$^{2}$. D) T$_{1/2}$ = 3/2kC$_{0}$. Show Answer Correct Answer: A) T$_{1/2}$ = 3/2kC$_{0}$$^{2}$. 14. If concentration of reactant 'A' is increased 10 times and the rate of reaction becomes 100 times. What is the order with respect to 'A'? A) 2. B) 3. C) 1. D) 4. Show Answer Correct Answer: A) 2. 15. Sophia, Abigail, and Oliver are conducting a chemistry experiment. They are observing how the reaction rates change. According to their observations, what can change the reaction rates? A) Changing the temperature of the experiment. B) Adding a catalyst to the experiment. C) Altering the concentration of the reactants. D) All of the above changes. Show Answer Correct Answer: D) All of the above changes. 16. The time required for 100% completion of a zero order reaction is A) [R$_{0}$]/k. B) 2k/[R$_{0}$]. C) [R$_{0}$]/2k. D) [R$_{0}$]k. Show Answer Correct Answer: A) [R$_{0}$]/k. 17. ..... reactions are those which are completed in more than one steps A) Simple. B) Parallel. C) Composite. D) All the above. Show Answer Correct Answer: C) Composite. 18. For the reaction A + 3B $\rightarrow$ 2C, how does the rate of disappearance of B compare to the rate of production of C? A) The rate of disappearance of B is 3/2 the rate of appearance of C. B) The rate of disappearance of B is the same as the rate of appearance of C. C) The rate of disappearance of B is 1/2 the rate of appearance of C. D) The rate of disappearance of B is twice the rate of appearance of C. Show Answer Correct Answer: A) The rate of disappearance of B is 3/2 the rate of appearance of C. 19. The role of a catalyst is to change ..... a) a. Gibbs energy of reaction. b) b. Enthalpy of reaction.c) c. Activation energy of reaction. d) d. Equilibrium constant A) C. B) D. C) B. D) A. Show Answer Correct Answer: A) C. 20. Which of the following represents the the unit of k in first order reaction? A) $s^{-1}$. B) $s$. C) $\frac{s}{M}$. D) None of the above. Show Answer Correct Answer: A) $s^{-1}$. 21. Increasing temperature of a chemical reaction: A) Increases the number of collisions per second of chemical reactants. B) Increases the speed of reaction. C) Can increase the pressure of reactants. D) All of the above. Show Answer Correct Answer: D) All of the above. 22. What is the parameter to measure the rate or speed of a reaction beside time? A) Change in pressure. B) Change in volume. C) Change in concentration. D) Change in temperature. Show Answer Correct Answer: C) Change in concentration. 23. The activation energy of a reaction can be determined from: A) Rate law. B) Stoichiometry. C) Arrhenius equation. D) Molecularity. Show Answer Correct Answer: C) Arrhenius equation. 24. In rate law expression:Rate = k [A]$^{p}$[B]$^{q}$, p and q are A) Coefficients of reactants A and B in the chemical reaction. B) Always constant for all the reactions. C) Determined experimentally. D) Can be determined by Collision theory. Show Answer Correct Answer: C) Determined experimentally. 25. In an exothermic reaction, the activation energy for the forward reaction is: A) Less than reverse reaction. B) Zero. C) Equal to reverse reaction. D) Greater than reverse reaction. Show Answer Correct Answer: A) Less than reverse reaction. 26. The rate constant increases with increasing temperature because: A) Catalyst is used. B) More molecules have energy greater than activation energy. C) Activation energy increases. D) Concentration increases. Show Answer Correct Answer: B) More molecules have energy greater than activation energy. 27. It is defined as the energy contained within a system. A) Enthalpy. B) Internal energy. C) Temperature. D) Heat. Show Answer Correct Answer: B) Internal energy. 28. What role does molecularity play in determining reaction rates? A) Molecularity determines the color change during a reaction. B) Molecularity determines the number of reactant molecules involved in a reaction, influencing the reaction rate through collision frequency. C) Molecularity is unrelated to the concentration of reactants. D) Molecularity only affects the temperature of a reaction. Show Answer Correct Answer: B) Molecularity determines the number of reactant molecules involved in a reaction, influencing the reaction rate through collision frequency. 29. Which of the following best describes why increasing temperature increase reaction rate? A) Activation energy is reduced. B) Collisions become more frequent. C) Collisions become more energetic. D) Collisions become more frequent and more energetic. Show Answer Correct Answer: D) Collisions become more frequent and more energetic. 30. Substance that speeds up chemical reactions but are not permanently changing themselves are called A) Inhibitors. B) Catalysts. C) Activators. D) Mechanisms. Show Answer Correct Answer: B) Catalysts. 31. What is the Arrhenius equation and its significance? A) The Arrhenius equation is used to determine the pH of a solution. B) The Arrhenius equation describes the relationship between temperature and reaction rates, highlighting the effect of activation energy. C) The Arrhenius equation calculates the concentration of reactants in a solution. D) The Arrhenius equation predicts the color change of a chemical reaction. Show Answer Correct Answer: B) The Arrhenius equation describes the relationship between temperature and reaction rates, highlighting the effect of activation energy. 32. 2 reactants which are dye (0.0001 M) and OH-(1.0 M) reacts to form products. The rate law for this reaction is Rate = k[OH-]$^{x}$[dye]$^{y}$ A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: B) False. 33. A 5.0-gram sample of zinc and a 50.-milliliter sample of hydrochloric acid are used in a chemical reaction. Which combination of these samples has the fastest reaction rate? A) A zinc strip and 1.0 M HCl(aq). B) A zinc strip and 3.0 M HCl(aq). C) Zinc powder and 1.0 M HCl(aq). D) Zinc powder and 3.0 M HCl(aq). Show Answer Correct Answer: D) Zinc powder and 3.0 M HCl(aq). 34. If the temperature is reduced, a reaction rate will ..... A) Increase. B) Decrease. C) Stay the same. D) None of the above. Show Answer Correct Answer: B) Decrease. 35. What is the definition of reaction rate in chemical kinetics? A) The temperature at which a chemical reaction occurs. B) The speed at which a chemical reaction takes place. C) The amount of reactants used in a chemical reaction. D) The color change observed during a chemical reaction. Show Answer Correct Answer: B) The speed at which a chemical reaction takes place. 36. For the reaction 2A+B$\rightarrow$C, if the rate law is Rate=k[A]$^{2}$, the molecularity and order are: A) 3, 3. B) 3, 2. C) 2, 3. D) 2, 2. Show Answer Correct Answer: B) 3, 2. 37. Two reactant particles collide with proper orientation.The collision will be effective if the particles have A) Sufficient potential energy. B) High activation energy. C) Sufficient kinetic energy. D) High ionization energy. Show Answer Correct Answer: C) Sufficient kinetic energy. 38. Decreasing the particle size increases the reaction rate because A) It makes particles move faster. B) It increases the likelihood of collisions with the correct geometry. C) It decreases the surface area available to react. D) More surface area allows an increase in the number of collisions. Show Answer Correct Answer: D) More surface area allows an increase in the number of collisions. 39. In a(n) ..... reaction, the reactants exist in two different phases A) Complex. B) Two-state. C) Intermediate. D) Heterogeneous. Show Answer Correct Answer: D) Heterogeneous. 40. For the reaction A + H$_{2}$O $\rightarrow$ products, find the rate of the reaction when [A] = 0.75 M, k= 0.02. A) 0.026 Ms$^{-1}$. B) 0.015 Ms$^{-1}$. C) 0.0003 Ms$^{-1}$. D) 0.02 Ms$^{-1}$. Show Answer Correct Answer: B) 0.015 Ms$^{-1}$. 41. What does the term 'pseudo first order' refer to? A) A reaction that is zero order. B) A reaction that has no order. C) A reaction that is first order in all conditions. D) A reaction that is actually second order but behaves like first order. Show Answer Correct Answer: D) A reaction that is actually second order but behaves like first order. 42. A catalyst changes the rate of a reaction by A. Changing pH.B. Increasing the temperature.C. Decreasing the energy of the products.D. Providing an alternate reaction mechanism. A) A. B) C. C) D. D) B. Show Answer Correct Answer: C) D. 43. Reaction rate means ..... A) Speed of reaction. B) Amount of product formed. C) Concentration of reacting particles. D) Combining reactants with products. Show Answer Correct Answer: A) Speed of reaction. 44. A 5% drug solution decomposes with a rate constant, k, of 0.05 /day. Calculate the time for the drug concentration to degrade to 2.5 mg/mL? A) 60 days. B) 3 days. C) 55 days. D) 60 hours. Show Answer Correct Answer: A) 60 days. 45. The following are the terms used to describe the relationship between the rate of a chemical reaction and the concentration of its reactants EXCEPT A) Differential rate laws. B) Chemical kinetics. C) Rate equations. D) Rate laws. Show Answer Correct Answer: B) Chemical kinetics. 46. Which of the following is an acceptable way to measure the reaction rate for the reaction between copper and silver nitrate?Cu(s) + 2AgNO$_{3}$(aq) $\rightarrow$ 2Ag(s) + Cu(NO$_{3}$)$_{2}$(aq) A) Change in conductivity. B) Change in mass. C) Change in volume of gas produced. D) Change in color (colorimetry). Show Answer Correct Answer: D) Change in color (colorimetry). 47. Which is the rate determining step in a chemical reaction? A) Fast step. B) Slow step. C) Step with least activation energy. D) None of the above. Show Answer Correct Answer: B) Slow step. 48. The reaction 3 A $\rightarrow$B +C would be a zero order reaction when A) The rate of reaction is proportional to square of concentration of A. B) The rate of reaction remains the same al any concentration of A. C) The rate of reaction doubles if concentration of B is increased to double. D) The rate remains unchanged at any concentration of B and C. Show Answer Correct Answer: B) The rate of reaction remains the same al any concentration of A. 49. The rate contant of a reaction is 3 x 10$^{-3 }$bar$^{-1}$sec$^{-1 }$what is the order A) Two. B) Zero. C) Three. D) One. Show Answer Correct Answer: A) Two. 50. Which of the following statements is true about the activation energy of a reaction? A) It is the energy required to maintain a reaction. B) It is the energy required to stop a reaction. C) It is the energy released during a reaction. D) It is the energy required to start a reaction. Show Answer Correct Answer: D) It is the energy required to start a reaction. 51. The first order constant rate unit is A) Time-1. B) Mass.time-1. C) Mass-1. D) None of the above. Show Answer Correct Answer: A) Time-1. 52. The rate constant for a reaction of zero order in A is 0.0030 mol L$^{-1}$s$^{-1}$. How long will it take for the initial concentration of A to fall from 0.10 M to 0.075 M . A) 1.62 s. B) 8.3 s. C) 0.162 s. D) 0.83 s. Show Answer Correct Answer: B) 8.3 s. 53. Mark the incorrect statements. a) Catalyst provides an alternative pathway to reaction mechanism. b) Catalyst only raises the activation energy.c) Catalyst lowers the activation energy. d) Catalyst alters enthalpy change of the reaction. A) C, D. B) A, b. C) B, D. D) A, C. Show Answer Correct Answer: C) B, D. 54. A catalyst is added to a reaction mixture. Which of the following is a likely outcome? A) The catalyst is consumed in the reaction. B) The reaction rate decreases. C) The activation energy of the reaction increases. D) The reaction reaches equilibrium faster. Show Answer Correct Answer: D) The reaction reaches equilibrium faster. 55. Which is a true statement about two Maxwell-Boltzman energy distribution curvesdrawn for a fixed amount of gas at two different temperatures, T K and (T+10) K? A) Both curves will peak at the same height. B) The area under both curves will be the same. C) Both curves will have the same number of particles with higher energy. D) He average energy for both curves will be the same. Show Answer Correct Answer: B) The area under both curves will be the same. 56. Under the same reaction conditions, initial concentration of 1.386 mol L$^{-1}$ of a substance becomes half in 40 seconds and 20 seconds through first order and zero order kinetics respectively. Ratio of the rate constants k$_{1}$/k$_{0}$ for first order (k$_{1}$) and zero order (k$_{0}$) of the reaction is A) 1 mol$^{-1}$ L. B) 2 mol$^{-1}$ L. C) 0.5 mol$^{-1}$ L. D) 1.5 mol$^{-1}$ L. Show Answer Correct Answer: C) 0.5 mol$^{-1}$ L. 57. As the concentration of reacting particles increases, the rate of reaction generally A) Decreases. B) Increases. C) Remains the same. D) None of the above. Show Answer Correct Answer: B) Increases. 58. An endothermic reaction absorbs heat, and an exothermic reaction releases heat. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 59. A chemical reaction that produces energy is a /an A) Energy. B) Endothermic reaction. C) Chemical reaction. D) Exothermic reaction. Show Answer Correct Answer: D) Exothermic reaction. 60. Zero-order reaction DOES NOT CHANGE WITH CONCENTRATION. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. ← 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 4Class 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 8Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 9 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books