Free Reaction Kinetics MCQs with Answers
573 Reaction Kinetics MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Reaction kinetics relates reaction rate to concentration, temperature, surface area and catalysts. Questions cover rate laws, reaction order, rate constants, activation energy and the activated complex, including how a catalyst lowers the activation energy without changing the overall energy change or equilibrium position.
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573 questions · page 23 of 29
- A. Concentration of reactants
- B. Amount of catalyst
- C. Concentration of products
- D. Rate of reaction
Explanation: The slope of a concentration-time graph for a chemical reaction gives the value of the reaction rate, therefore option D is correct.
Correct answer: Rate of reaction- A. Increase
- B. Become constant
- C. Decreases
- D. Becomes zero
Explanation: At zero, it is a horizontal line/sleeping line on the x-axis, therefore option D is correct.
Correct answer: Becomes zero- A. Substance in excess
- B. Catalyst
- C. Substance in small amount
- D. Quantity of product
Explanation: Option C is correct since the substance is in smaller quantity, it will act as a limiting reagent and decide the rate of reaction.
Correct answer: Substance in small amount- A. Temperature
- B. Polarity
- C. Refractive Index
- D. Packing
Explanation: Option A is correct as temperature affects the frequency of the collision of molecules.
Correct answer: Temperature- A. Temperature
- B. Volume
- C. Pressure
- D. Specific gravity
Explanation: Option C is correct because the pressure will compress and decompress the molecules of the gas and hence will be able to increase and…
Correct answer: Pressure- A. Concentration
- B. Pressure
- C. Volume
- D. Collision frequency
Explanation: Option D is correct the higher the collision frequency between reacting molecules, the greater the probability of successful collisions…
Correct answer: Collision frequency- A. Faster
- B. Equal in speed
- C. Slower
- D. None of the above
Explanation: Redox reactions are slower than ionic reactions because they involve the transfer of electrons, which is a slower process than the…
Correct answer: Slower- A. 5g
- B. 10g
- C. 15g
- D. 20g
Explanation: To determine the amount of substance remaining after 10 hours, calculate the number of half-lives that have passed.
Correct answer: 10g- A. 1
- B. 1/3
- C. 1/2
- D. 2
Explanation: The order of reaction can be determined by examining how the rate changes with varying concentrations of the reactant.
Correct answer: 1/3- A. 28s
- B. 42s
- C. (14)2s
- D. (14)3s
Explanation: For a first-order reaction, the half-life is the time it takes for the concentration to reduce to half its initial value.
Correct answer: 42s- A. Among the reactants
- B. Among the products
- C. Reactants and the products
- D. None of the above
Explanation: Activation energy, denoted as Ea, is the minimum energy required to initiate a chemical reaction.
Correct answer: Among the reactants452. Which of the following best explains the effects of a catalyst on the rate of a reversible reaction?
- A. It decreases the rate of the reverse reaction.
- B. It increases the kinetic energy of the reacting molecules.
- C. It moves the equilibrium position to the right.
- D. It provides a new reaction path with a lower activation energy.
Explanation: A catalyst affects the rate of a reversible reaction by providing an alternative pathway with a lower activation energy, thereby…
Correct answer: It provides a new reaction path with a lower activation energy.- A. Zymase
- B. Invertase
- C. Maltase
- D. None of these
Explanation: Invertase is the correct enzyme responsible for the hydrolysis of sucrose into glucose and fructose.
Correct answer: Invertase- A. Electrical conductivity method
- B. Dilatometeric method
- C. Refractometric method
- D. Optical rotation method
Explanation: The electrical conductivity method is the most appropriate for measuring the rate of reaction when it depends on the rate of change in the…
Correct answer: Electrical conductivity method- A. 1
- B. 2
- C. 3
- D. 0
Explanation: The decomposition of N2O5 is described by a three-step mechanism. The first step, N2O5 → NO2 + NO3, is the slowest and thus the…
Correct answer: 1- A. 2 and 2
- B. 6 and 2
- C. 8 and 3
- D. 8 and 2
Explanation: Given: Rate law = Rate = k[FeCl₃]¹[KI]¹Overall order = 1 + 1 = 2Molecularity = number of species colliding in an elementary step.
Correct answer: 2 and 2- A. are found
- B. is found
- C. have found
- D. were found
Explanation: B) is found is the correct answer because 'each' is a singular subject and requires a singular verb.
Correct answer: is found- A. Ample
- B. Cramped
- C. Stagnant
- D. Dormant
Explanation: Capacious is synonymous to roomy, having a generous amount of space.
Correct answer: Ample- A. startled
- B. arm
- C. themselves
- D. took up
Explanation: "Took up" is incorrect. The phrase "took up" suggests an additional action of assuming a position or stance, which changes the meaning of…
Correct answer: took up- A. It's
- B. Joke
- C. As they went
- D. Into
Explanation: The sentence "You think it's a practical joke." she asked as they went into the room contains a period (.) after "joke", which makes the…
Correct answer: Joke