All flashcards
Flashcard 1: What is the effect of a catalyst on the rate constant k?
Answer: A catalyst increases the rate constant k. Higher k values result from the lower activation energy pathway.
Flashcard 2: What is the active site in enzyme catalysis?
Answer: The active site is the region of an enzyme where substrate binds. This specific binding site determines the enzyme's catalytic specificity.
Flashcard 3: Do catalysts affect the overall stoichiometry of a reaction?
Answer: No, catalysts do not affect the overall stoichiometry. Catalysts change reaction pathways but not the balanced chemical equation.
Flashcard 4: What is the effect of temperature on catalytic activity?
Answer: Increasing temperature generally increases catalytic activity. Higher temperatures provide more kinetic energy for catalyst-reactant interactions.
Flashcard 5: Identify an example of a catalyst in an everyday product.
Answer: Platinum in catalytic converters of vehicles. It converts toxic exhaust gases into less harmful substances.
Flashcard 6: Does a catalyst alter the equilibrium constant of a reaction?
Answer: No, a catalyst does not change the equilibrium constant. Catalysts only affect reaction rates, not the thermodynamic equilibrium position.
Flashcard 7: What is the primary role of a catalyst in a reaction mechanism?
Answer: To lower the activation energy and accelerate the reaction. Catalysts enable faster reaction rates by reducing energy barriers.
Flashcard 8: What is meant by 'catalyst poisoning'?
Answer: Deactivation of a catalyst by impurities. Poisoning reduces or eliminates the catalyst's ability to function effectively.
Flashcard 9: What is the principle behind the use of catalysts in green chemistry?
Answer: To reduce the need for energy and minimize waste production. Catalysts enable more efficient, environmentally friendly chemical processes.
Flashcard 10: How does a catalyst affect the rate of a reaction?
Answer: A catalyst increases the rate of a reaction. It provides an alternative pathway with lower activation energy.
Flashcard 11: How does a catalyst affect the Gibbs free energy (△G) of a reaction?
Answer: A catalyst does not affect the Gibbs free energy change. Catalysts change kinetics but not the overall energy change of reactions.
Flashcard 12: What type of catalysis involves an enzyme?
Answer: Biocatalysis involves enzymes. Enzymes are biological catalysts that accelerate metabolic reactions.
Flashcard 13: What is a heterogeneous catalyst?
Answer: A catalyst in a different phase than the reactants. The catalyst exists in a different state of matter from the reactants.
Flashcard 14: What is an enzyme in the context of catalysis?
Answer: An enzyme is a biological catalyst. Enzymes are proteins that catalyze biochemical reactions in living organisms.
Flashcard 15: Identify one advantage of using catalysts in industrial processes.
Answer: Catalysts can increase efficiency and reduce energy consumption. They enable faster reactions at lower temperatures, saving energy costs.
Flashcard 16: What is the role of a support in heterogeneous catalysis?
Answer: A support provides a surface for the catalyst to disperse. Supports increase surface area and prevent catalyst particle aggregation.
Flashcard 17: Is a catalyst consumed during a chemical reaction?
Answer: No, a catalyst is not consumed in the reaction. It participates in the reaction but is regenerated in the final step.
Flashcard 18: Identify the main difference between homogeneous and heterogeneous catalysts.
Answer: Homogeneous catalysts are in the same phase as reactants; heterogeneous are not. Phase differences affect separation, recovery, and reaction mechanisms.
Flashcard 19: What is the definition of a catalyst in chemistry?
Answer: A substance that increases reaction rate without being consumed. It speeds up reactions by providing an alternative pathway but remains unchanged after the reaction.
Flashcard 20: What is the effect of a catalyst on the rate constant k?
Answer: A catalyst increases the rate constant k. Higher k values result from the lower activation energy pathway.
Flashcard 21: What is a homogeneous catalyst?
Answer: A catalyst in the same phase as the reactants. Both catalyst and reactants exist in the same state of matter.
Flashcard 22: Does a catalyst change the reaction mechanism?
Answer: Yes, a catalyst provides an alternative reaction mechanism. The mechanism involves the catalyst in intermediate steps.
Flashcard 23: What is 'catalyst regeneration'?
Answer: The process by which a catalyst is restored to its original state. This allows the catalyst to be reused multiple times.
Flashcard 24: What is a catalytic cycle?
Answer: A sequence of steps involving a catalyst that regenerates the catalyst. The catalyst is consumed and regenerated in a repeating sequence.
Flashcard 25: How does a catalyst affect the time required to reach equilibrium?
Answer: A catalyst reduces the time required to reach equilibrium. Faster kinetics mean equilibrium is achieved more quickly.
Flashcard 26: What is an enzyme in the context of catalysis?
Answer: An enzyme is a biological catalyst. Enzymes are proteins that catalyze biochemical reactions in living organisms.
Flashcard 27: Does a catalyst change the reaction mechanism?
Answer: Yes, a catalyst provides an alternative reaction mechanism. The mechanism involves the catalyst in intermediate steps.
Flashcard 28: What is 'catalyst regeneration'?
Answer: The process by which a catalyst is restored to its original state. This allows the catalyst to be reused multiple times.
Flashcard 29: How does a catalyst affect the time required to reach equilibrium?
Answer: A catalyst reduces the time required to reach equilibrium. Faster kinetics mean equilibrium is achieved more quickly.
Flashcard 30: What is the active site in enzyme catalysis?
Answer: The active site is the region of an enzyme where substrate binds. This specific binding site determines the enzyme's catalytic specificity.