Class 12 Chemistry Ch-4 Chemical Kinetics MCQs Exam 2027

Unit 4: Chemical Kinetics

Topic: Rate of Reaction and Rate Law

1. The equilibrium constant $K_p$ for the chemical reaction $H_2(g) + I_2(g) \rightleftharpoons 2HI(g)$ depends on: [BSEB, 2015 A, 2016 C]

   (A) Total pressure

   (B) Catalyst

   (C) Amounts of $H_2$ and $I_2$

   (D) Temperature

2. The rate at which a substance reacts depends on its: [BSEB, 2020 A, 2024 A]

   (A) Active mass

   (B) Molecular weight

   (C) Atomic weight

   (D) Equivalent weight

3. The rate of a chemical reaction: [BSEB, 2022 A]

   (A) Increases with time

   (B) Decreases with time

   (C) May increase or decrease with time

   (D) Remains constant with time

4. For a chemical reaction $2A + B \to C$, the rate of reaction can be represented by: [BSEB, 2023 A]

   (A) $-\frac{1}{2} \frac{d[A]}{dt}$

   (B) $-\frac{d[B]}{dt}$

   (C) $\frac{+d[C]}{dt}$

   (D) All of these

5. The rate expression for a chemical reaction is, Rate $= k[A][B]^n$; the order of the reaction is: [BSEB, 2025 A]

   (A) 1

   (B) $n$

   (C) $n+1$

   (D) None of these

6. What is the unit of the rate of a chemical reaction? [BSEB, 2012 A]

   (A) $mol \ L^{-1}$

   (B) $mol \ L^{-1} \ sec^{-1}$

   (C) $mol \ sec^{-1}$

   (D) $L \ mol^{-1} \ sec^{-1}$

7. Active Mass means: [BSEB, 2013 A]

   (A) Molar concentration

   (B) Gram per litre

   (C) Equivalent weight

   (D) Atomic weight

8. For a reaction $aA + bB \rightarrow \text{Product}$, $\frac{-d[A]}{dt}$ is equal to: [BSEB, 2026]

   (A) $\frac{-d[B]}{dt}$

   (B) $\frac{-b}{a} \frac{d[B]}{dt}$

   (C) $\frac{-a}{b} \frac{d[B]}{dt}$

   (D) $\frac{-b}{d} \frac{d[B]}{dt}$

9. If for the reaction $A \to B$, $-d[A]/dt = 2 d[B]/dt$, the rate law of the reaction is: [BSEB, 2018 C]

   (B) $d[B]/dt = k[A]$

10. If the rate of a reaction is $Rate = k[A]^x[B]^y$, then the overall order is: [BSEB, 2012 A]

    (A) $x \times y$

    (B) $x – y$

    (C) $x + y$

    (D) $x/y$

Topic: Order of Reaction (Zero, First, and Second Order)

11. The time required for 100% completion of a zero-order reaction is: [BSEB, 2021 A]

    (A) $a/k$

    (B) $k/a$

    (C) $a/2k$

    (D) $2k/a$

12. The unit of the rate constant for a zero-order reaction is: [BSEB, 2021 A]

    (A) $L \ sec^{-1}$

    (B) $L \ mol^{-1}$

    (C) $mol \ sec^{-1}$

    (D) $mol \ L^{-1} \ sec^{-1}$

13. For a zero-order reaction $A + B \to C$, the rate is: [BSEB, 2021 A]

    (A) $Rate = K[A]^0[B]^0$

    (B) $Rate = K[A]^1[B]^0$

    (C) $Rate = K[A]^0[B]^1$

    (D) None of these

14. For a zero-order reaction: [BSEB, 2017 A]

    (A) $t_{1/2} \propto a$

    (B) $t_{1/2} \propto 1/a$

    (C) $t_{1/2} \propto a^2$

    (D) $t_{1/2} \propto 1/a^2$

15. For which order of reaction are the units of rate and rate constant the same? [BSEB, 2021 A]

    (A) Zero

    (B) First

    (C) Second

    (D) None of these

16. The rate of a zero-order reaction: [BSEB, 2025 A]

    (A) Is constant

    (B) Decreases with time

    (C) Increases with time

    (D) Sometimes decreases, sometimes increases

17. The value of $t_{1/2}$ for a first-order reaction is: [BSEB, 2016 A, 2020 A]

    (A) $0.6/k$

    (B) $0.693/k$

    (C) $0.10/k$

    (D) $0.93/k$

18. The unit of rate constant for a first-order reaction is: [BSEB, 2011 A, 2024 A]

    (A) $sec^{-1}$

    (B) $mol \ L^{-1} \ sec^{-1}$

    (C) $L \ mol^{-1} \ sec^{-1}$

    (D) $mol \ L^{-1}$

19. For a first-order reaction, the value of $t_{90\%}$ is: [BSEB, 2022 A]

    (A) $1.1 \times t_{1/2}$

    (B) $2.2 \times t_{1/2}$

    (C) $3.3 \times t_{1/2}$

    (D) $4.4 \times t_{1/2}$

20. The half-life of a first-order reaction: [BSEB, 2023 A]

    (A) Does not depend on the rate constant

    (B) Does not depend on the initial concentration

    (C) Depends on the initial concentration

    (D) All of these

21. The half-life of a first-order reaction is 100 seconds; its rate constant will be: [BSEB, 2014 A]

    (A) $6.93 \times 10^{-3} \ s^{-1}$

    (B) $6.93 \times 10^{-4} \ s^{-1}$

    (C) $0.693 \ s^{-1}$

    (D) $0.0693 \ s^{-1}$

22. $t_{1/2} \propto \frac{1}{a^2}$ indicates that the chemical reaction is: [BSEB, 2017 A]

    (A) A first-order reaction

    (B) A second-order reaction

    (C) A third-order reaction

    (D) A complex reaction

23. The unit of rate constant for a second-order reaction is: [BSEB, 2022 A]

    (A) $mol^{-1} \ L \ sec^{-1}$

    (B) $mol \ L^{-1} \ sec^{-1}$

    (C) $sec^{-1}$

    (D) $mol \ L \ sec^{-1}$

24. For a reaction $aA \rightarrow bB + \text{Product}$, $\frac{-d[A]}{dt}$ is equal to: [BSEB, 2026]

    (A) $\frac{-d[B]}{dt}$

    (B) $\frac{-b}{d} \frac{d[B]}{dt}$

    (C) $\frac{-a}{b} \frac{d[B]}{dt}$

    (D) $\frac{-b}{a} \frac{d[B]}{dt}$

25. For a reaction $A \to B$, the rate is expressed as $r = k[A]^n$. If $n=2$, the order of reaction is: [BSEB, 2013 A]

    (A) Zero

    (B) First

    (C) Second

    (D) Third

26. The molecularity of a reaction cannot be: [BSEB, 2014 A]

    (A) 1

    (B) 2

    (C) 0 or fractional

    (D) 3

27. The order of the inversion of sugar is: [BSEB, 2015 A]

    (A) Zero

    (B) First

    (C) Second

    (D) Third

28. An example of a pseudo-first-order reaction is: [BSEB, 2024 A]

    (A) Acidic hydrolysis of ester

    (B) Decomposition of $N_2O_5$

    (C) Decomposition of $H_2O_2$

    (D) Formation of $Cl_2$

29. Hydrolysis of ethyl acetate in acidic medium is an example of: [BSEB, 2018 A]

    (A) Zero-order reaction

    (B) First-order reaction

    (C) Second-order reaction

    (D) Third-order reaction

30. Hydrolysis of ethyl acetate in the presence of dilute NaOH is a reaction of which order? [BSEB, 2025 A]

    (A) 1

    (B) 2

    (C) 3

    (D) 0

31. The order of the reaction $H_2(g) + Cl_2(g) \xrightarrow{h\nu} 2HCl(g)$ is: [BSEB, 2011 A, 2018 C]

    (A) Zero order

    (B) First order

    (C) Second order

    (D) None of these

32. What will be the order of the reaction $H_2 + Cl_2 \xrightarrow{h\nu} 2HCl$? [BSEB, 2021 A]

    (A) 0

    (B) 1

    (C) 2

    (D) 3

33. For a chemical reaction $A \to B$, if the concentration of A is increased 4 times, the rate becomes double. The order of reaction is: [BSEB, 2018 A]

    (A) 2

    (B) 1

    (C) $1/2$

    (D) 0

34. The rate equation of a reaction is $dx/dt = k[H]^{1/2}[B]^{1/2}$, the order of reaction is: [BSEB, 2024 A]

    (A) 2

    (B) $1/2$

    (C) $3/2$

    (D) 1

35. The rate equation of a chemical reaction is represented as: $Rate = k[A][B]^2$. If the concentration of A is kept constant and B is tripled, the rate: [BSEB, 2023 A]

    (A) Becomes double

    (B) Becomes triple

    (C) Becomes four times

    (D) Becomes nine times

36. Radioactive decay is a reaction of which order? [BSEB, 2026]

    (A) Zero order

    (B) First order

    (C) Second order

    (D) Third order

37. Radioactive decay is a: [BSEB, 2026]

    (A) Zero-order reaction

    (B) First-order reaction

    (C) Second-order reaction

    (D) Third-order reaction

38. Which of the following is NOT a first-order reaction? [BSEB, 2022 A, 2024 A]

    (A) $CH_3COOC_2H_5 + H_2O \xrightarrow{H^+} CH_3COOH + C_2H_5OH$

    (B) $CH_3COOC_2H_5 + NaOH \to CH_3COONa + C_2H_5OH$

    (C) $2H_2O_2 \to 2H_2O + O_2$

    (D) $2N_2O_5 \to 4NO_2 + O_2$

39. The chemical reaction $2O_3 \to 3O_2$ occurs as: $O_3 \rightleftharpoons O_2 + O$ (fast), $O + O_3 \to 2O_2$ (slow). The rate equation is: [BSEB, 2022 A]

    (A) Rate $= K[O_3]^2$

    (B) Rate $= K[O_3]^2 [O_2]^{-1}$

    (C) Rate $= K[O_3] [O_2]$

    (D) Rate $= K[O_3] [O_2]^2$

40. What can be the order of a reaction? [BSEB, 2025 A]

    (A) Only integer

    (B) Only zero

    (C) Zero, integer or fractional

    (D) Only positive

Topic: Effect of Temperature and Arrhenius Equation

41. Arrhenius equation is: [BSEB, 2021 A]

    (A) $k = Ae^{-E_a/RT}$

    (B) $k = Ae^{E_a/RT}$

    (C) $k = -Ae^{-E_a/RT}$

    (D) $k = -Ae^{E_a/RT}$

42. According to Arrhenius equation, the slope of the graph between $\log k$ vs $1/T$ is: [BSEB, 2023 A]

    (A) $-E_a/R$

    (B) $-E_a/2.303R$

    (C) $E_a/2.303R$

    (D) $R/E_a$

43. For most reactions, the value of the temperature coefficient lies between: [BSEB, 2022 A]

    (A) 2 and 3

    (B) 1 and 2

    (C) 2 and 4

    (D) 3 and 4

44. The rate constant (k) of a reaction depends on: [BSEB, 2018 A, 2021 A]

    (A) Temperature

    (B) Concentration

    (C) Weight

    (D) Time

45. In a chemical reaction, the value of Slope is plotted between: [BSEB, 2025 A]

    (A) Temperature and Pressure

    (B) Pressure and Concentration

    (C) $\log K$ and $1/T$

    (D) Temperature and $\sqrt{P}$

46. Which of the following shows the effect of temperature on the reaction rate? [BSEB, 2026]

    (A) Nernst equation

    (B) Gibbs-Helmholtz equation

    (C) Arrhenius equation

    (D) Van’t Hoff equation

47. The activation energy of a chemical reaction can be determined by: [BSEB, 2022 A]

    (A) Determining the rate constants at two different temperatures

    (B) Determining the rate constant at standard temperature

    (C) Changing the concentration

    (D) None of these

48. The temperature coefficient for most reactions lies between: [BSEB, 2025 A]

    (A) 1 and 3

    (B) 2 and 3

    (C) 1 and 4

    (D) 2 and 4

49. If the excitation energy (activation energy) of forward and backward reactions is the same, then: [BSEB, 2018 C]

    (A) $\Delta H = 0$

    (B) $\Delta S = 0$

    (C) Zero-order reaction

    (D) None of these

50. At $T = \infty$, the rate constant $k$ will be equal to: [BSEB, 2026]

    (A) 0

    (B) $A$ (Arrhenius factor)

    (C) $1$

    (D) $e$

Topic: Activation Energy and Threshold Energy

51. In Arrhenius equation, $e^{-E_a/RT}$ represents: [BSEB, 2025 A]

    (A) Fraction of molecules having energy greater than or equal to $E_a$

    (B) Total number of molecules

    (C) Rate of reaction

    (D) Value of activation energy

52. In a chemical reaction, ‘Threshold Energy’ is: [BSEB, 2023 A]

    (A) Activation energy + Average energy of molecules

    (B) Activation energy – Average energy of molecules

    (C) Average energy of molecules

    (D) None of these

53. The minimum energy required for reactant molecules to be converted into products is: [BSEB, 2021 A]

    (A) Kinetic energy

    (B) Potential energy

    (C) Activation energy

    (D) Kinetic energy + Potential energy

54. For a reaction, $\Delta H$ is negative. The relation between activation energy $E_a$ and backward activation energy $E_{a,rev}$ will be: [BSEB, 2026]

    (A) $E_{a,rev} > E_a$

    (B) $E_a > E_{a,rev}$

    (C) $E_a = E_{a,rev}$

    (D) $E_a = 0$

55. The half-life of a first-order reaction does not depend on: [BSEB, 2017 C]

    (A) Initial concentration of reactant

    (B) Temperature

    (C) Pressure

    (D) None of these

Topic: Catalysts and Other Factors

56. A catalyst increases the rate of reaction because it: [BSEB, 2020 A]

    (A) Lowers the activation energy

    (B) Increases the activation energy

    (C) Increases the temperature

    (D) Decreases the pressure

57. In any reaction, a catalyst: [BSEB, 2020 A]

    (A) Decreases reaction rate

    (B) Increases reaction rate

    (C) Increases and decreases reaction rate

    (D) None of these

58. A catalyst is a substance which: [BSEB, 2019 A]

    (A) Increases the equilibrium concentration of product

    (B) Changes the equilibrium constant of the reaction

    (C) Shortens the time to reach equilibrium

    (D) Provides energy to the reaction

59. A catalyst is a substance that: [BSEB, 2014 A]

    (A) Only increases the rate

    (B) Only decreases the rate

    (C) Changes the rate

    (D) Keeps the rate constant

60. In the presence of a catalyst, activation energy ($E_a$): [BSEB, 2019 A]

    (A) Decreases

    (B) Increases

    (C) Remains unchanged

    (D) Becomes zero

61. Which of the following is used as a catalyst in the manufacture of ammonia by Haber’s process? [BSEB, 2023 A]

    (A) Finely divided iron

    (B) Finely divided molybdenum

    (C) Finely divided nickel

    (D) Finely divided platinum

62. In $N_2 + 3H_2 \rightleftharpoons 2NH_3$, $Fe$ acts as: [BSEB, 2025 A]

    (A) Reactant

    (B) Catalyst

    (C) Product

    (D) Promoter

63. Substances that increase the power of a catalyst are: [BSEB, 2020 A]

    (A) Catalytic poisons

    (B) Catalytic promoters

    (C) Inhibitors

    (D) None of these

64. How do catalysts lose their activity? [BSEB, 2015 C]

    (A) On heating

    (B) By catalytic poisons

    (C) By reducing pressure

    (D) None of these

65. What is the role of an intermediate in a chemical reaction? [BSEB, 2016 C]

    (A) To increase the rate

    (B) To complete the reaction

    (C) To provide an alternative path

    (D) None of these

66. Which is used to prevent the decomposition of $H_2O_2$? [BSEB, 2026]

    (A) $NaCl$

    (B) Glycerol or Acetanilide

    (C) $FeCl_3$

    (D) $NaOH$

67. The main source of Solar Energy is: [BSEB, 2019 A]

    (A) Nuclear fission

    (B) Nuclear fusion

    (C) Chemical reaction

    (D) Burning of coal

Unit 5: Surface Chemistry

Topic: Adsorption

68. The process of adsorption is a: [BSEB, 2023 A]

    (A) Interfacial phenomenon

    (B) Surface phenomenon

    (C) Diffusion phenomenon

    (D) None of these

69. How many layers are formed in chemical adsorption (Chemisorption)? [BSEB, 2021 A]

    (A) One

    (B) Two

    (C) Many

    (D) Zero

70. In physical adsorption, gas particles are held to the solid surface by which force? [BSEB, 2020 A]

    (A) Chemical force

    (B) Electrostatic force

    (C) Gravitational force

    (D) Van der Waals forces

71. The nature of chemical adsorption is: [BSEB, 2022 A]

    (A) Reversible

    (B) Irreversible

    (C) Fast

    (D) Physical

72. Heat of adsorption ($\Delta H_{ad}$) for physical adsorption is: [BSEB, 2019 A]

    (A) 20-40 kJ/mol

    (B) 80-240 kJ/mol

    (C) 100-200 kJ/mol

    (D) 400 kJ/mol

73. Adsorption of a gas on a solid surface is: [BSEB, 2018 A]

    (A) Endothermic

    (B) Exothermic

    (C) Irreversible

    (D) None of these

74. The value of Free Energy ($G$) in adsorption: [BSEB, 2026]

    (A) Increases

    (B) Decreases

    (C) Remains zero

    (D) Is infinite

75. According to Freundlich adsorption isotherm: [BSEB, 2019 A]

    (A) $\frac{x}{m} = kP^{1/n}$

    (B) $\frac{x}{m} = kP^{n}$

    (C) $\frac{x}{m} = kP^0$

    (D) None of these

76. The correct expression for Langmuir’s adsorption isotherm is: [BSEB, 2026]

    (A) $\frac{x}{m} = \frac{1+aP}{b}$

    (B) $\frac{x}{m} = \frac{aP}{1+bP}$

    (C) $\frac{x}{m} = \frac{1+aP}{1+bP}$

    (D) $\frac{x}{m} = \frac{1}{a} + \frac{bP}{a}$

77. What is the order of adsorption of gases $H_{2}, CH_{4}, CO_{2}$ and $NH_{3}$ by 1 gram of charcoal at 288 K? [BSEB, 2026]

    (A) $H_{2} > CH_{4} > CO_{2} > NH_{3}$

    (B) $CH_{4} > CO_{2} > NH_{3} > H_{2}$

    (C) $CO_{2} > NH_{3} > H_{2} > CH_{4}$

    (D) $NH_{3} > CO_{2} > CH_{4} > H_{2}$

Topic: Colloidal State

78. The size of colloidal particles is: [BSEB, 2026]

    (A) 1 nm – 10 nm

    (B) 10 nm – 100 nm

    (C) 1 nm – 1000 nm

    (D) 10 nm – 1000 nm

79. The average size of colloidal particles is: [BSEB, 2026]

    (A) $10^{-10}$ m

    (B) $10^{-9}$ m to $10^{-6}$ m

    (C) $10^{-12}$ m

    (D) $10^{-3}$ m

80. Smoke is a colloidal state in which: [BSEB, 2026]

    (A) Gas is dispersed in solid

    (B) Solid is dispersed in gas

    (C) Gas is dispersed in gas

    (D) Liquid is dispersed in gas

81. Fog is an example of: [BSEB, 2023 A]

    (A) Solid in gas

    (B) Liquid in gas

    (C) Gas in liquid

    (D) Solid in gas

82. Cloud is an example of: [BSEB, 2024 A]

    (A) Dispersion of solid in gas

    (B) Dispersion of liquid in gas

    (C) Dispersion of gas in liquid

    (D) Dispersion of liquid in liquid

83. Butter is an example of: [BSEB, 2026]

    (A) Gel

    (B) Emulsion

    (C) Sol

    (D) Foam

84. Cheese is an example of: [BSEB, 2023 A]

    (A) Sol

    (B) Gel

    (C) Emulsion

    (D) Foam

85. The colloidal type of soap lather is: [BSEB, 2026]

    (A) Gel

    (B) Foam

    (C) Sol

    (D) Emulsion

86. A colloidal solution of solid in solid is called: [BSEB, 2018 A]

    (A) Sol

    (B) Solid Sol

    (C) Gel

    (D) Aerosol

87. Pumice stone is an example of: [BSEB, 2026]

    (A) Liquid in solid

    (B) Gas in solid

    (C) Solid in liquid

    (D) Gas in solid

88. Lyophobic colloids are: [BSEB, 2015 A]

    (A) Reversible

    (B) Irreversible

    (C) Stable

    (D) None of these

89. An example of Lyophilic colloid is: [BSEB, 2011 A]

    (A) Sulphur sol

    (B) Gum

    (C) $As_2S_3$ sol

    (D) Gold sol

90. Milk is: [BSEB, 2012 A]

    (A) Fat dispersed in water

    (B) Water dispersed in fat

    (C) Fat dispersed in fat

    (D) None of these

91. The main reason for the stability of colloidal particles is: [BSEB, 2024 A]

    (A) Charge on particles

    (B) Brownian motion

    (C) Tyndall effect

    (D) Size of particles

92. The charge on colloidal particles is detected by: [BSEB, 2020 A]

    (A) Dialysis

    (B) Tyndall effect

    (C) Electrophoresis

    (D) Brownian motion

93. What is the charge on blood? [BSEB, 2022 A]

    (A) Positive

    (B) Negative

    (C) Neutral

    (D) Zero

Topic: Properties of Colloids (Tyndall, Brownian, Coagulation)

94. Tyndall Effect is found in: [BSEB, 2016 A]

    (A) Solution

    (B) Precipitate

    (C) Sol (Colloid)

    (D) Vapour

95. The blue colour of the sky is due to: [BSEB, 2014 A]

    (A) Refraction

    (B) Diffraction

    (C) Scattering of light (Tyndall Effect)

    (D) Reflection

96. The cause of Brownian Movement is: [BSEB, 2021 A]

    (A) Temperature fluctuation

    (B) Gravitational force

    (C) Collision of molecules of dispersion medium with colloidal particles

    (D) Size of particles

97. The zigzag motion of colloidal particles is called: [BSEB, 2013 A]

    (A) Tyndall effect

    (B) Brownian motion

    (C) Peptization

    (D) Diffusion

98. Hardy-Schulze rule is related to: [BSEB, 2022 A]

    (A) Adsorption

    (B) Coagulation

    (C) Dialysis

    (D) Tyndall effect

99. The most effective ion in coagulating $Fe(OH)_3$ sol is: [BSEB, 2016 C]

    (A) $Cl^-$

    (B) $SO_4^{2-}$

    (C) $[Fe(CN)_6]^{4-}$

    (D) $PO_4^{3-}$

100. ‘Gold Number’ is related to: [BSEB, 2018 A]

     (A) Protective colloid

     (B) Emulsion

     (C) Gel

     (D) None of these

101. The lower the Gold number, the protective power: [BSEB, 2026]

     (A) Higher it will be

     (B) Lower it will be

     (C) No effect

     (D) Will be zero

102. Gelatin is used: [BSEB, 2017 C]

     (A) As a protective colloid

     (B) As an emulsifier

     (C) As a catalyst

     (D) As an adsorbent

103. In Peptization: [BSEB, 2017 A]

     (A) Precipitate dissolves

     (B) Precipitate converts into colloidal solution

     (C) Colloid settles down

     (D) Electrolyte is removed

104. The process opposite to coagulation is called: [BSEB, 2019 A]

     (A) Dialysis

     (B) Peptization

     (C) Adsorption

     (D) Condensation

105. Purification of colloids is done by which method? [BSEB, 2017 A]

     (A) Filtration

     (B) Evaporation

     (C) Dialysis

     (D) Condensation

106. The solution that can pass through animal membrane is: [BSEB, 2016 A]

     (A) True solution

     (B) Colloidal solution

     (C) Suspension

     (D) All of these

107. Purification of colloidal particles is highly effective by: [BSEB, 2026]

     (A) Simple dialysis

     (B) Electro-dialysis

     (C) Filtration

     (D) Sedimentation

108. Purification of water by Alum is based on: [BSEB, 2021 A]

     (A) Dialysis

     (B) Adsorption

     (C) Coagulation

     (D) Peptization

109. Micelle formation occurs only above which temperature? [BSEB, 2025 A]

     (A) Freezing point

     (C) Kraft temperature ($T_k$)

     (B) Boiling point

     (D) Normal temperature

110. What does CMC stand for? [BSEB, 2026]

     (A) Critical Micelle Concentration

     (B) Common Micelle Code

     (C) Chemical Micelle Class

     (D) None of these

Topic: Emulsion and Catalysis

111. Which of the following substances acts as an Emulsifier? [BSEB, 2026]

     (A) Common salt

     (B) Urea

     (C) Soap

     (D) Oil

112. Which protein found in milk acts as an emulsifier? [BSEB, 2026]

     (A) Haemoglobin

     (B) Myoglobin

     (C) Casein

     (D) Albumin

113. Which of the following is a Biological catalyst? [BSEB, 2026]

     (A) Carbohydrate

     (B) Enzyme

     (C) Amino acid

     (D) Nitrogenous base

114. Enzyme activity is maximum at: [BSEB, 2024 A]

     (A) Low temperature

     (B) High temperature

     (C) Optimum Temperature

     (D) 0°C

115. Which of the following is a Shape selective catalyst? [BSEB, 2026]

     (A) $V_{2}O_{5}$

     (B) $Cr_{2}O_{3}$

     (C) $MnO_{2}$

     (D) ZSM-5

116. Which of the following enzymes converts sugar into glucose and fructose? [BSEB, 2022 A]

     (A) Zymase

     (B) Invertase

     (C) Maltase

     (D) Diastase

117. Conversion of milk into curd is an example of: [BSEB, 2015 A]

     (A) Decomposition

     (B) Fermentation

     (C) Emulsification

     (D) None of these

118. The unit of Arrhenius factor ($A$) is same as that of: [BSEB, 2026]

     (A) Activation energy

     (B) Temperature

     (C) Rate constant ($k$)

     (D) Time

119. The reaction $RCOOAg + Br_2 \xrightarrow{CCl_4} RBr + AgBr + CO_2$ is called: [BSEB, 2022 A]

     (A) HVZ reaction

     (B) Hunsdiecker reaction

     (C) Hoffmann reaction

     (D) Carbylamine reaction

120. The main source of Solar Energy is: [BSEB, 2019 A]

     (A) Nuclear fission

     (B) Nuclear fusion

     (C) Chemical reaction

     (D) Burning of coal

Unit 4 & 5: Other Important & Repeat Questions

121. For a first-order reaction, the value of $k$ is $2 \times 10^{-2} \ s^{-1}$. $t_{1/2}$ will be: [BSEB, 2011 A]

     (A) 20 s

     (B) 34.65 s

     (C) 100 s

     (D) 50 s

122. The rate of reaction of any substance depends on: [BSEB, 2017 A]

     (A) Atomic weight

     (B) Equivalent weight

     (C) Molecular weight

     (D) Active weight (mass)

123. The value of slope for the plot of $\log_{10} k$ vs $1/T$ in Arrhenius equation is: [BSEB, 2023 A]

     (A) $-E_a/R$

     (B) $-E_a/2.303R$

     (C) $E_a/2.303R$

     (D) $A$

124. The half-life of a radioactive element is 10 minutes. Its average life will be: [BSEB, 2017 A]

     (A) 14.4 minutes

     (B) 6.93 minutes

     (C) 10 minutes

     (D) 20 minutes

125. The rate of a zero-order reaction: [BSEB, 2025 A]

     (A) Is constant

     (B) Decreases with time

     (C) Increases with time

     (D) Sometimes decreases, sometimes increases

126. Catalyst is a substance which changes the rate of chemical reaction: [BSEB, 2014 A]

     (A) Only increases

     (B) Only decreases

     (C) Changes

     (D) Keeps constant

127. Gas particles are held on solid surface in physical adsorption by: [BSEB, 2020 A]

     (A) Chemical force

     (B) Electrostatic force

     (C) Gravitational force

     (D) Van der Waals forces

128. Purification of colloids is carried out by: [BSEB, 2017 A]

     (A) Filtration

     (B) Evaporation

     (C) Dialysis

     (D) Condensation

129. Tyndall effect is observed in: [BSEB, 2016 A]

     (A) Solution

     (B) Precipitate

     (C) Sol (Colloid)

     (D) Vapour

130. Charge on blood is: [BSEB, 2022 A]

     (A) Positive

     (B) Negative

     (C) Neutral

     (D) Zero

131. Gold number is associated with: [BSEB, 2018 A]

     (A) Protective colloid

     (B) Emulsion

     (C) Gel

     (D) None of these

132. Fog is an example of: [BSEB, 2023 A]

     (A) Solid in gas

     (B) Liquid in gas

     (C) Gas in liquid

     (D) Solid in gas

133. Lyophobic colloids are: [BSEB, 2015 A]

     (A) Reversible

     (B) Irreversible

     (C) Stable

     (D) None of these

134. Maximum activity of enzyme is at: [BSEB, 2024 A]

     (A) Low temp

     (B) High temp

     (C) Optimum temp

     (D) 0°C

135. Unit of rate constant for first-order reaction is: [BSEB, 2011 A, 2024 A]

     (A) $sec^{-1}$

     (B) $mol \ L^{-1} \ sec^{-1}$

     (C) $L \ mol^{-1} \ sec^{-1}$

     (D) $mol \ L^{-1}$

136. In any reaction, a catalyst: [BSEB, 2020 A]

     (A) Decreases rate

     (B) Increases rate

     (C) Increases and decreases rate

     (D) None of these

137. Hydrolysis of ethyl acetate is an example of: [BSEB, 2018 A]

     (A) Zero order

     (B) First order

     (C) Second order

     (D) Third order

138. Milk turning into curd is an example of: [BSEB, 2015 A]

     (A) Decomposition

     (B) Fermentation

     (C) Emulsification

     (D) None of these

139. Catalyst used in Haber’s process is: [BSEB, 2023 A]

     (A) Fine iron powder

     (B) Molybdenum powder

     (C) Nickel powder

     (D) Platinum powder

140. For $A \to B$, if $[A]$ is 4 times, rate is doubled. Order is: [BSEB, 2018 A]

     (A) 2

     (B) 1

     (C) $1/2$

     (D) 0

141. Zigzag motion of colloidal particles is: [BSEB, 2013 A]

     (A) Tyndall effect

     (B) Brownian motion

     (C) Peptization

     (D) Diffusion

142. Order of $H_2 + Cl_2 \xrightarrow{h\nu} 2HCl$ is: [BSEB, 2021 A]

     (A) 0

     (B) 1

     (C) 2

     (D) 3

143. Unit of rate constant for zero-order reaction: [BSEB, 2021 A]

     (A) $L \ sec^{-1}$

     (B) $L \ mol^{-1}$

     (C) $mol \ sec^{-1}$

     (D) $mol \ L^{-1} \ sec^{-1}$

144. $t_{1/2}$ for first-order reaction is: [BSEB, 2016 A, 2020 A]

     (A) $0.6/k$

     (B) $0.693/k$

     (C) $0.10/k$

     (D) $0.93/k$

145. Slope of $\log k$ vs $1/T$ graph is: [BSEB, 2023 A]

     (A) $-E_a/R$

     (B) $-E_a/2.303R$

     (C) $E_a/2.303R$

     (D) $R/E_a$

146. Rate constant depends on: [BSEB, 2023 A]

     (A) Temperature

     (B) Amount

     (C) Weight

     (D) Time

147. Temperature coefficient lies between: [BSEB, 2022 A]

     (A) 2 and 3

     (B) 1 and 2

     (C) 2 and 4

     (D) 3 and 4

148. Rate of reaction of any substance depends on: [BSEB, 2017 A]

     (A) Atomic weight

     (B) Equivalent weight

     (C) Molecular weight

     (D) Active mass

149. Order of $H_2(g) + Cl_2(g) \xrightarrow{h\nu} 2HCl(g)$ is: [BSEB, 2011 A, 2018 C]

     (A) Zero order

     (B) First order

     (C) Second order

     (D) None of these

150. Rate constant (k) depends on: [BSEB, 2018 A, 2021 A]

     (A) Temperature

     (B) Concentration

     (C) Weight

     (D) Time