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 10 of 29
- A. Amount of Substrate.
- B. Catalyst
- C. Temperature
- D. All of these.
Explanation: The major factors upon which the rate of a chemical reaction depends are:Amount of substrate/Concentration,Temperature,Catalyst…
Correct answer: All of these.- A. Get faster
- B. None of these
- C. Stops
- D. Slow Down
Explanation: Before a collision, molecules tend to slow down instantaneously in order to react with each other.
Correct answer: Slow Down- A. Proper energy
- B. In a homogeneous mixture
- C. All of these
- D. Proper orientation
Explanation: For a chemical reaction to take place, the molecules have to collide with proper energy, orientation and must be in a homogenous mixture…
Correct answer: All of these- A. All of these
- B. Universal gas constant "R"
- C. Activation energy
- D. Collision frequency of reacting substance
Explanation: In the Arrhenius equation, (k = rate constant, A = pre-exponential factor, Ea = activation energy, R = universal gas constant, T =…
Correct answer: Collision frequency of reacting substance- A. Increasing surface area
- B. By increasing effective collisions
- C. Increasing activation energy barrier
- D. By lowering activation energy
Explanation: The minimum energy required to initiate a chemical reaction is called activation energy.
Correct answer: By lowering activation energy- A. Depends on reactant concentration
- B. Constant quantity
- C. Changes with time
- D. Units are mol/dm³s
Explanation: The rate of reaction changes with time and is dependent on reactant concentration, temperature and presence of a catalyst.
Correct answer: Constant quantity- A. Product formation directly
- B. Reactant activation
- C. Activated complex formation
- D. Intermediate formation
Explanation: An activated complex is an unstable arrangement of atoms that has the highest energy.
Correct answer: Activated complex formation- A. Reactant
- B. Product
- C. Reagent
- D. Catalyst
Explanation: A catalyst increases the rate of reaction by lowering the activation energy of the reaction.
Correct answer: Catalyst- A. Double decomposition reactions
- B. Neutralisation
- C. Ionic reactions
- D. All of these
Explanation: Reactions that take a very short time to reach completion are termed fast reactions.
Correct answer: All of these- A. K¯
- B. J/mol K
- C. K
- D. Mol/K
Explanation: The slope is given by -Ea/2.303R. The units for activation energy or Ea are Jmol−1 and those for R are JK−1mol−1.
Correct answer: K- A. Rate of reaction
- B. Instantaneous rate
- C. Rate of multistep reaction
- D. Average rate
Explanation: Average rate is the rate of reaction between a specific period of time.
Correct answer: Average rate- A. No units
- B. Unit of Moles/dm3
- C. Unit as Moles / litre
- D. Unit as Moles/dm3.s
Explanation: Rate of reaction = change in product concentration/time taken, hence its units are mol.dm-3s-1
Correct answer: Unit as Moles/dm3.s- A. Temperature
- B. Pressure
- C. Time
- D. None of these
Explanation: Option A: The rate of change of concentration with respect to temperature would be represented as dC/dT, where dC is the change in…
Correct answer: Time- A. First order
- B. Second order
- C. Any order
- D. Zero order
Explanation: Option A: First order: For a reaction that follows first-order kinetics, the half-life is constant and is independent of the initial…
Correct answer: Any order- A. Decrease in concentration
- B. Increase in concentration
- C. Increase in yield
- D. Decrease in temperature
Explanation: Option A: Decrease in concentration: If the rate expression for products had a negative sign, it would indicate that the rate of the…
Correct answer: Increase in concentration- A. Critical step
- B. Rate Limiting step
- C. Final Step
- D. None of these
Explanation: The rate-determining step is also called the slowest step because it is the step with the highest activation energy and the slowest rate.
Correct answer: Rate Limiting step- A. 700 Million years
- B. 706 Million years
- C. 89 days
- D. 710 million years
Explanation: The half life of Uranium is 710 million years.
Correct answer: 710 million years- A. First order
- B. Second order
- C. Third order
- D. Zero order
Explanation: A first-order reaction is a type of chemical reaction in which the rate of the reaction is directly proportional to the concentration of…
Correct answer: First order- A. Reactant concentration
- B. Product concentration
- C. Slowest step
- D. All of these options are correct
Explanation: OPTION A: The rate of reaction is dependent more on the concentration of reactants.
Correct answer: Reactant concentration- A. Completed instantaneously
- B. Slow
- C. Economical
- D. None of these options is correct
Explanation: The rates of reaction and their control are important in the industry. They are sometimes the deciding factors that determine whether a…
Correct answer: Economical