1. A catalyst is a substance that:
A) Increases activation energy
B) Increases equilibrium constant
C) Speeds up the reaction without being consumed
D) Gets permanently consumed in the reaction
Answer: C
Explanation: A catalyst lowers activation energy and accelerates the reaction without itself being consumed.
2. Which of the following is not a characteristic of a catalyst?
A) It remains unchanged at the end
B) It alters equilibrium constant
C) It alters rate of reaction
D) It functions even in small amounts
Answer: B
Explanation: Catalysts do not change the equilibrium constant; they only help reach equilibrium faster.
3. The branch of chemistry that deals with catalysts is called:
A) Thermodynamics
B) Catalysis
C) Photochemistry
D) Electrochemistry
Answer: B
Explanation: Catalysis is the study of catalysts and catalytic processes.
4. Which of the following is a homogeneous catalyst?
A) V₂O₅ in Contact process
B) Fe in Haber’s process
C) H⁺ ions in ester hydrolysis
D) Ni in hydrogenation
Answer: C
Explanation: Homogeneous catalysts exist in the same phase as reactants, e.g., H⁺ ions in ester hydrolysis.
5. Which of the following is a heterogeneous catalyst?
A) HCl in hydrolysis
B) NO in oxidation of SO₂
C) Pt in hydrogenation
D) H₂SO₄ in esterification
Answer: C
Explanation: In hydrogenation, solid Pt acts as a catalyst for gaseous reactants → heterogeneous catalysis.
6. Which catalyst is used in the Haber’s process for ammonia synthesis?
A) V₂O₅
B) Fe
C) Pt
D) MnO₂
Answer: B
Explanation: Iron catalyst is used in the Haber process (with promoters like K₂O, Al₂O₃).
7. In the Contact process (manufacture of H₂SO₄), the catalyst used is:
A) Fe₂O₃
B) V₂O₅
C) Ni
D) Pt
Answer: B
Explanation: Vanadium pentoxide (V₂O₅) catalyzes oxidation of SO₂ to SO₃.
8. Which type of catalysis does hydrogenation of vegetable oils using Ni belong to?
A) Homogeneous
B) Heterogeneous
C) Autocatalysis
D) Negative catalysis
Answer: B
Explanation: Solid Ni catalyst with liquid oil and gaseous H₂ → heterogeneous catalysis.
9. Enzymes act as:
A) Negative catalysts
B) Homogeneous catalysts
C) Heterogeneous catalysts
D) Inhibitors
Answer: B
Explanation: Enzymes act in the same aqueous phase as the substrate → homogeneous catalysis.
10. The “lock and key” model is associated with:
A) Autocatalysis
B) Enzyme catalysis
C) Inhibition
D) Surface catalysis
Answer: B
Explanation: The model explains how enzymes specifically bind substrates.
11. The catalyst in the Ostwald process (manufacture of nitric acid) is:
A) V₂O₅
B) Pt-Rh gauze
C) Fe
D) Ni
Answer: B
Explanation: Pt-Rh gauze catalyzes oxidation of NH₃ to NO.
12. Catalytic converters in automobiles typically use:
A) Fe and Cu
B) Pt, Pd, and Rh
C) Ni and Zn
D) Mn and Cr
Answer: B
Explanation: Platinum, Palladium, and Rhodium catalyze oxidation of CO and hydrocarbons, and reduction of NOx.
13. The process where product itself acts as a catalyst is called:
A) Homogeneous catalysis
B) Autocatalysis
C) Heterogeneous catalysis
D) Inhibition
Answer: B
Explanation: In autocatalysis, the reaction product accelerates the reaction.
14. Which is an example of autocatalysis?
A) Ester hydrolysis
B) Oxidation of SO₂
C) Decomposition of oxalic acid by KMnO₄
D) Haber’s process
Answer: C
Explanation: Mn²⁺ formed in the reaction catalyzes further decomposition → autocatalysis.
15. Negative catalysts are also called:
A) Promoters
B) Poisons
C) Enzymes
D) Substrates
Answer: B
Explanation: Poisons slow down reactions by destroying catalyst activity.
16. A promoter in catalysis is:
A) A substance that increases efficiency of a catalyst
B) A catalyst inhibitor
C) An alternative reactant
D) A solvent
Answer: A
Explanation: Promoters enhance activity of catalysts (e.g., K₂O in Haber’s process).
17. Example of promoter in Haber’s process is:
A) Al₂O₃
B) K₂O
C) Both A and B
D) NaCl
Answer: C
Explanation: Al₂O₃ and K₂O increase efficiency of Fe catalyst.
18. Which reaction uses MnO₂ as a catalyst?
A) Decomposition of H₂O₂
B) Oxidation of SO₂
C) Haber’s process
D) Esterification
Answer: A
Explanation: MnO₂ catalyzes decomposition of hydrogen peroxide into water and oxygen.
19. Which catalyst is used in hydrogenation of oils?
A) V₂O₅
B) Fe
C) Ni
D) Pt
Answer: C
Explanation: Finely divided Nickel is most common hydrogenation catalyst.
20. Which catalyst is used in Deacon’s process (manufacture of Cl₂)?
A) V₂O₅
B) CuCl₂
C) Fe₂O₃
D) Ni
Answer: B
Explanation: CuCl₂ catalyzes oxidation of HCl to Cl₂.
21. Which is an example of heterogeneous catalysis?
A) Hydrolysis of esters
B) Oxidation of SO₂ by NO
C) Haber’s process (Fe catalyst)
D) Enzyme action
Answer: C
Explanation: Fe solid catalyst with gaseous reactants is heterogeneous.
22. Catalysis in which reactants and catalyst are in same phase is called:
A) Homogeneous catalysis
B) Heterogeneous catalysis
C) Autocatalysis
D) Enzyme catalysis
Answer: A
Explanation: Same phase → homogeneous catalysis.
23. Catalysis in which reactants and catalyst are in different phases is called:
A) Homogeneous
B) Heterogeneous
C) Enzyme
D) Inhibition
Answer: B
Explanation: Different phases → heterogeneous catalysis.
24. The most efficient catalysts are:
A) Metals
B) Acids
C) Enzymes
D) Alkalis
Answer: C
Explanation: Enzymes (biocatalysts) are highly efficient and specific.
25. The theory explaining heterogeneous catalysis is:
A) Collision theory
B) Intermediate compound theory
C) Adsorption theory
D) Quantum theory
Answer: C
Explanation: Adsorption theory explains catalytic action on solid surfaces.
26. The adsorption theory of catalysis is mainly applicable to:
A) Homogeneous catalysis
B) Heterogeneous catalysis
C) Autocatalysis
D) Enzyme catalysis
Answer: B
Explanation: Adsorption theory explains surface catalysis in heterogeneous reactions.
27. According to adsorption theory, the role of catalyst is to:
A) Increase temperature of reactants
B) Increase concentration of products
C) Provide a surface for adsorption of reactants
D) Change equilibrium constant
Answer: C
Explanation: Catalyst surface adsorbs reactants, weakens bonds, and facilitates reaction.
28. In heterogeneous catalysis, reactants are adsorbed on the surface by:
A) Diffusion
B) Condensation
C) Adsorption forces
D) Hydrogen bonding
Answer: C
Explanation: Adsorption forces (physisorption or chemisorption) hold molecules on catalyst surface.
29. Which type of adsorption is more important in catalysis?
A) Physical adsorption
B) Chemical adsorption
C) Capillary adsorption
D) Molecular adsorption
Answer: B
Explanation: Chemisorption forms strong bonds, activating molecules for reaction.
30. Which of the following is an example of adsorption catalysis?
A) Hydrolysis of ester by acid
B) Hydrogenation of ethene on Ni
C) Decomposition of ozone by Cl atoms
D) Decomposition of H₂O₂ by I⁻
Answer: B
Explanation: Hydrogenation occurs via chemisorption of H₂ and alkene on Ni surface.
31. Which factor does not affect adsorption catalysis?
A) Surface area of catalyst
B) Temperature
C) Presence of promoter or poison
D) Avogadro number
Answer: D
Explanation: Adsorption depends on surface, temp, and promoters/poisons, not on Avogadro constant.
32. A catalyst increases the rate of reaction because:
A) It increases collision frequency
B) It decreases activation energy
C) It increases heat of reaction
D) It alters equilibrium
Answer: B
Explanation: Catalyst provides an alternative pathway with lower activation energy.
33. Which is correct regarding catalyst action?
A) Catalyst changes ΔG of reaction
B) Catalyst changes enthalpy of reaction
C) Catalyst changes activation energy
D) Catalyst shifts equilibrium
Answer: C
Explanation: Only activation energy is altered; ΔG, ΔH, equilibrium remain unchanged.
34. Which catalyst is used in hydrogenation of benzene to cyclohexane?
A) Ni
B) Fe
C) V₂O₅
D) Pt
Answer: A
Explanation: Finely divided Ni catalyzes hydrogenation of benzene.
35. Which process uses Fe as a catalyst?
A) Ostwald process
B) Haber process
C) Contact process
D) Deacon’s process
Answer: B
Explanation: Haber process (NH₃ manufacture) uses Fe catalyst with promoters.
36. Which process uses V₂O₅ as a catalyst?
A) Ostwald process
B) Contact process
C) Haber process
D) Deacon’s process
Answer: B
Explanation: Contact process for SO₂ → SO₃ uses V₂O₅.
37. Which catalyst is used in Ostwald process?
A) Pt-Rh gauze
B) V₂O₅
C) Ni
D) Fe
Answer: A
Explanation: Ammonia oxidation uses Pt-Rh catalyst.
38. Which catalyst is used in the synthesis of methanol from CO and H₂?
A) Fe
B) Cu-ZnO-Al₂O₃
C) Pt
D) Ni
Answer: B
Explanation: Methanol synthesis uses Cu-ZnO-Al₂O₃ catalyst.
39. Which process uses Ziegler–Natta catalyst?
A) Production of NH₃
B) Hydrogenation of oils
C) Polymerization of alkenes
D) Manufacture of H₂SO₄
Answer: C
Explanation: Ziegler–Natta catalysts (TiCl₄ + AlEt₃) are used for alkene polymerization.
40. What is the function of promoters in catalysis?
A) To increase activity of catalyst
B) To decrease catalyst efficiency
C) To stop catalyst poisoning
D) To act as secondary reactant
Answer: A
Explanation: Promoters enhance activity of catalysts without themselves being catalysts.
41. Example of a promoter in Haber’s process is:
A) Cu
B) K₂O
C) ZnO
D) MnO₂
Answer: B
Explanation: K₂O and Al₂O₃ promote Fe catalyst in ammonia synthesis.
42. Catalyst poison in Haber’s process is:
A) H₂S
B) O₂
C) H₂O
D) N₂
Answer: A
Explanation: H₂S deactivates Fe catalyst by poisoning.
43. Which industrial process uses Ni as catalyst?
A) Haber process
B) Contact process
C) Hydrogenation of oils
D) Ostwald process
Answer: C
Explanation: Nickel catalyzes hydrogenation of vegetable oils.
44. Which industrial process uses CuCl₂ as a catalyst?
A) Deacon’s process
B) Contact process
C) Ostwald process
D) Haber process
Answer: A
Explanation: CuCl₂ catalyzes HCl oxidation in Deacon’s process.
45. Which process uses TiCl₄ and Al(C₂H₅)₃ as catalysts?
A) Haber process
B) Ziegler–Natta polymerization
C) Ostwald process
D) Contact process
Answer: B
Explanation: Ziegler–Natta catalysts for polyethylene/polypropylene manufacture.
46. The role of catalyst in chemical reaction is to:
A) Change heat of reaction
B) Increase ΔH of system
C) Provide alternate pathway with lower activation energy
D) Increase product concentration
Answer: C
Explanation: Catalyst lowers activation energy by offering alternate mechanism.
47. Which is an example of catalytic converter in cars?
A) Ni
B) Pt-Pd-Rh
C) Fe
D) V₂O₅
Answer: B
Explanation: Pt, Pd, and Rh catalysts are used in vehicle catalytic converters.
48. Which type of catalyst is Ziegler–Natta catalyst?
A) Homogeneous
B) Heterogeneous
C) Enzyme
D) Negative
Answer: B
Explanation: Solid TiCl₄ and AlEt₃ catalysts are heterogeneous.
49. Which of the following is an example of a negative catalyst?
A) Glycerol in decomposition of H₂O₂
B) MnO₂ in decomposition of H₂O₂
C) V₂O₅ in Contact process
D) Ni in hydrogenation
Answer: A
Explanation: Glycerol slows decomposition of H₂O₂ → negative catalyst.
50. Which is an example of catalytic hydrogenation?
A) C₂H₄ → C₂H₆ using Ni
B) H₂O₂ → H₂O + O₂ using MnO₂
C) NH₃ → NO using Pt
D) SO₂ → SO₃ using V₂O₅
Answer: A
Explanation: Nickel catalyzes hydrogenation of ethene to ethane.
51. Enzymes are chemically:
A) Carbohydrates
B) Proteins
C) Lipids
D) Nucleic acids
Answer: B
Explanation: Enzymes are biological catalysts made of proteins (sometimes conjugated with cofactors).
52. Which of the following is not an enzyme?
A) Urease
B) Amylase
C) Catalase
D) Insulin
Answer: D
Explanation: Insulin is a hormone, not an enzyme.
53. The enzyme that catalyzes decomposition of H₂O₂ into water and oxygen is:
A) Amylase
B) Catalase
C) Urease
D) Lipase
Answer: B
Explanation: Catalase rapidly decomposes hydrogen peroxide.
54. Enzyme catalysis is an example of:
A) Homogeneous catalysis
B) Heterogeneous catalysis
C) Autocatalysis
D) Negative catalysis
Answer: A
Explanation: Enzyme and substrate are usually in same aqueous phase → homogeneous catalysis.
55. The “lock and key” hypothesis was proposed by:
A) Arrhenius
B) Berzelius
C) Fischer
D) Ostwald
Answer: C
Explanation: Emil Fischer (1894) proposed “lock and key” model of enzyme action.
56. The enzyme that converts glucose into ethanol and CO₂ is:
A) Zymase
B) Invertase
C) Maltase
D) Amylase
Answer: A
Explanation: Zymase in yeast catalyzes alcoholic fermentation of glucose.
57. The enzyme used in hydrolysis of urea is:
A) Zymase
B) Urease
C) Catalase
D) Amylase
Answer: B
Explanation: Urease catalyzes conversion of urea into NH₃ and CO₂.
58. Which of the following is an example of enzyme catalysis in the human body?
A) Hydrolysis of starch by amylase
B) SO₂ oxidation by V₂O₅
C) Hydrogenation by Ni
D) NH₃ synthesis by Fe
Answer: A
Explanation: Amylase in saliva hydrolyzes starch to maltose.
59. The efficiency of enzymes is highest at:
A) Low temperature
B) Optimum temperature and pH
C) Very high temperature
D) Any condition
Answer: B
Explanation: Enzymes work best at an optimum temperature and pH (e.g., 37 °C for human enzymes).
60. Which is an example of autocatalysis?
A) Hydrolysis of esters
B) Oxidation of SO₂
C) Decomposition of oxalic acid by KMnO₄
D) Haber process
Answer: C
Explanation: Mn²⁺ formed in the reaction accelerates further decomposition.
61. Autocatalysis is a process in which:
A) Reactants act as catalyst
B) Products act as catalyst
C) Promoters act as catalyst
D) Solvent acts as catalyst
Answer: B
Explanation: In autocatalysis, the product of reaction accelerates the same reaction.
62. Which is a classical example of autocatalysis?
A) Esterification
B) Decomposition of oxalic acid by KMnO₄
C) Haber’s process
D) Contact process
Answer: B
Explanation: Mn²⁺ ions formed act as catalyst in further decomposition.
63. Negative catalysis is also known as:
A) Catalysis
B) Inhibition
C) Promotion
D) Adsorption
Answer: B
Explanation: Negative catalysts (poisons) reduce rate of reaction by inhibiting catalyst action.
64. An example of negative catalysis is:
A) MnO₂ in H₂O₂ decomposition
B) Glycerol in decomposition of H₂O₂
C) Pt in H₂ + O₂ reaction
D) Ni in hydrogenation
Answer: B
Explanation: Glycerol retards decomposition of H₂O₂.
65. Which of the following is a negative catalyst for oxidation of chloroform?
A) Alcohol
B) Phenol
C) Oxygen
D) Acetic acid
Answer: A
Explanation: Ethyl alcohol prevents oxidation of chloroform to poisonous phosgene → negative catalyst.
66. The theory of intermediate compound formation explains:
A) Homogeneous catalysis
B) Heterogeneous catalysis
C) Negative catalysis
D) Autocatalysis
Answer: A
Explanation: In homogeneous catalysis, catalyst reacts with reactant to form unstable intermediate → speeds up reaction.
67. Which theory explains heterogeneous catalysis?
A) Collision theory
B) Adsorption theory
C) Intermediate compound theory
D) Chain reaction theory
Answer: B
Explanation: Adsorption theory explains heterogeneous catalysis on solid surfaces.
68. In intermediate compound theory, catalyst:
A) Forms stable compounds with reactants
B) Forms unstable intermediates with reactants
C) Forms permanent compounds with products
D) Remains unreactive
Answer: B
Explanation: Catalyst forms unstable intermediates that decompose to products, regenerating catalyst.
69. The main difference between positive and negative catalysis is:
A) Positive catalyst increases rate, negative decreases it
B) Positive catalyst decreases rate, negative increases it
C) Both increase rate
D) Both decrease rate
Answer: A
Explanation: Positive → increases rate; Negative → retards reaction.
70. Which of the following is a catalytic poison?
A) H₂S for Fe in Haber process
B) Al₂O₃ for Fe in Haber process
C) K₂O for Fe in Haber process
D) Pt for NH₃ oxidation
Answer: A
Explanation: H₂S poisons Fe catalyst in Haber process.
71. Which factor strongly influences enzyme catalysis?
A) Temperature and pH
B) Only pressure
C) Only concentration of substrate
D) Only surface area
Answer: A
Explanation: Enzyme activity depends heavily on optimum temperature and pH.
72. Enzyme catalysis is often described by:
A) Adsorption theory
B) Intermediate compound theory
C) Lock and key hypothesis
D) Arrhenius equation
Answer: C
Explanation: Lock and key model best explains enzyme action.
73. The efficiency of catalysis depends upon:
A) Activation energy
B) Heat of reaction
C) Equilibrium constant
D) Specific heat
Answer: A
Explanation: Lower the activation energy by catalyst, higher the efficiency.
74. Which theory can explain both homogeneous and enzyme catalysis?
A) Adsorption theory
B) Intermediate compound theory
C) Collision theory
D) Lock and key model
Answer: B
Explanation: Intermediate compound theory applies well to homogeneous and enzyme catalysis.
75. A catalyst that stops working due to poisoning can sometimes be restored by:
A) Increasing reactant concentration
B) Removing the poison
C) Adding heat of reaction
D) Adding more products
Answer: B
Explanation: Removal of catalyst poison can restore catalytic activity.
76. Which catalyst is used in the manufacture of nitric acid (Ostwald process)?
A) Fe
B) Pt-Rh gauze
C) V₂O₅
D) Ni
Answer: B
Explanation: In Ostwald process, Pt-Rh gauze catalyzes oxidation of NH₃ to NO.
77. Which process uses Fe catalyst with promoters K₂O and Al₂O₃?
A) Contact process
B) Haber process
C) Ostwald process
D) Deacon’s process
Answer: B
Explanation: Haber process (ammonia synthesis) uses Fe with promoters.
78. Which catalyst is used in hydrogenation of oils?
A) Ni
B) V₂O₅
C) CuCl₂
D) Fe₂O₃
Answer: A
Explanation: Finely divided Ni is common catalyst for hydrogenation of oils.
79. In Deacon’s process (manufacture of Cl₂), the catalyst is:
A) Pt
B) CuCl₂
C) Fe
D) Ni
Answer: B
Explanation: CuCl₂ catalyzes oxidation of HCl to Cl₂.
80. In catalytic converters of cars, which metals are used?
A) Pt, Pd, Rh
B) Fe, Cu
C) Ni, Zn
D) Cr, Mn
Answer: A
Explanation: Pt, Pd, and Rh reduce NOx and oxidize CO and hydrocarbons.
81. Which catalyst is used for oxidation of SO₂ to SO₃ in Contact process?
A) Pt
B) V₂O₅
C) Ni
D) Fe
Answer: B
Explanation: Vanadium pentoxide (V₂O₅) catalyzes SO₂ → SO₃.
82. Ziegler–Natta catalysts are used in:
A) Polymerization of alkenes
B) Decomposition of H₂O₂
C) Hydrolysis of esters
D) Oxidation of NH₃
Answer: A
Explanation: Ziegler–Natta catalysts (TiCl₄ + AlEt₃) polymerize alkenes like ethene, propene.
83. Which catalyst is used in methanol synthesis from CO + H₂?
A) Ni
B) Fe
C) Cu–ZnO–Al₂O₃
D) Pt
Answer: C
Explanation: Methanol synthesis uses Cu–ZnO–Al₂O₃.
84. Which catalyst is used in Wacker process (oxidation of ethene to acetaldehyde)?
A) PdCl₂–CuCl₂
B) Ni
C) Pt
D) Fe
Answer: A
Explanation: Wacker process uses PdCl₂–CuCl₂ as catalysts.
85. Which is an example of photocatalysis?
A) Photosynthesis
B) Decomposition of H₂O₂ by MnO₂
C) Haber process
D) Contact process
Answer: A
Explanation: Photosynthesis is catalyzed by chlorophyll under light → photocatalysis.
86. Which catalyst is used in Fischer–Tropsch process (coal → liquid fuels)?
A) Fe or Co
B) Ni
C) Cu
D) Pt
Answer: A
Explanation: Fischer–Tropsch process uses Fe or Co catalysts.
87. Which is an example of autocatalysis in biology?
A) DNA replication
B) Photosynthesis
C) Respiration
D) Hydrolysis of starch
Answer: A
Explanation: DNA replication is autocatalytic because the product (DNA) helps catalyze its own synthesis.
88. The function of a catalyst in equilibrium reaction is to:
A) Change equilibrium constant
B) Increase rate of forward reaction only
C) Increase rate of both forward and backward reactions equally
D) Increase yield of product
Answer: C
Explanation: Catalyst speeds up both directions equally → equilibrium reached faster, not shifted.
89. Catalyst increases rate of reaction by:
A) Increasing activation energy
B) Decreasing activation energy
C) Increasing free energy
D) Increasing enthalpy
Answer: B
Explanation: Catalyst lowers activation energy by providing alternate pathway.
90. In Haber process, a catalyst poison is:
A) H₂S
B) CO₂
C) O₂
D) H₂O
Answer: A
Explanation: H₂S poisons Fe catalyst.
91. The most specific and efficient catalysts are:
A) Metals
B) Enzymes
C) Acids
D) Alkalis
Answer: B
Explanation: Enzymes are highly specific biocatalysts.
92. Which catalyst is used in catalytic cracking in petroleum industry?
A) Pt/Al₂O₃
B) Ni
C) Fe
D) V₂O₅
Answer: A
Explanation: Catalytic cracking uses Pt or zeolite catalysts on alumina support.
93. Which catalyst is used in Haber–Bosch process for NH₃?
A) Fe + K₂O/Al₂O₃ promoters
B) Pt–Rh gauze
C) V₂O₅
D) Ni
Answer: A
Explanation: Haber–Bosch process uses Fe with K₂O, Al₂O₃ promoters.
94. Which catalyst is used in synthesis of acetic acid from methanol + CO (Monsanto process)?
A) RhI₂
B) Ni
C) Pt
D) Fe
Answer: A
Explanation: Monsanto process uses Rh catalyst (RhI₂(CO)₂⁻ complex).
95. Which catalyst is used in hydrodesulfurization of petroleum?
A) Co–Mo–Al₂O₃
B) Pt
C) Ni
D) V₂O₅
Answer: A
Explanation: Cobalt–Molybdenum catalyst on alumina support removes sulfur from petroleum.
96. Which catalyst is used in decomposition of KClO₃ to O₂?
A) MnO₂
B) Fe₂O₃
C) V₂O₅
D) Ni
Answer: A
Explanation: MnO₂ catalyzes KClO₃ decomposition to O₂.
97. Which is the main advantage of catalyst in industry?
A) Increases cost of production
B) Reduces time and energy required
C) Decreases yield
D) Changes product composition
Answer: B
Explanation: Catalyst lowers energy requirement and speeds up reaction → economical.
98. Which is a heterogeneous catalyst in Haber process?
A) Fe solid
B) NH₃
C) H₂
D) N₂
Answer: A
Explanation: Fe (solid) acts as heterogeneous catalyst with gaseous reactants.
99. Which is the role of promoters like K₂O in Haber process?
A) Acts as poison
B) Increases activity of Fe catalyst
C) Decreases rate
D) Absorbs NH₃
Answer: B
Explanation: Promoters increase efficiency of main catalyst.
100. Which statement about catalysts is correct?
A) Catalyst alters equilibrium constant
B) Catalyst is consumed in reaction
C) Catalyst lowers activation energy
D) Catalyst changes ΔH of reaction
Answer: C
Explanation: Catalyst provides alternative pathway with lower activation energy, but does not change ΔH or equilibrium constant.