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 12 of 29
- A. Rate
- B. Time concentration
- C. Reaction yield
- D. Concentration
Explanation: The brackets in the rate expression shows the concentration of the reactants and products.
Correct answer: Concentration- A. Temperature
- B. Concentration
- C. Pressure
- D. Activation Energy
Explanation: If you plot a graph of [A] vs. t and draw a line tangent to the graph, then rate = ½ × |slope| of the line (rate is always a positive…
Correct answer: Concentration- A. Area under the curve
- B. Calculating length of curve
- C. Drawing a tangent to the curve
- D. All of these
Explanation: Slope or gradient can be determined by drawing tangent. Construct the tangent to a curve at a certain point A, you draw a line that…
Correct answer: Drawing a tangent to the curve- A. Lower than the instantaneous rate
- B. Higher than the instantaneous rate
- C. Equal to the instantaneous rate
- D. None of these options is correct
Explanation: In the beginning, the instantaneous rate is higher than the average rate.
Correct answer: Higher than the instantaneous rate- A. Completed instantaneously
- B. Slow
- C. Economical
- D. None of these options are correct
Explanation: Option C is correct since the ultimate goal of any industry is to make as much money as possible which is possible economically.
Correct answer: Economical- A. Throughout the reaction
- B. Near reaction completion
- C. At one instant only
- D. At the start of the reaction
Explanation: The only time when the average rate and the instantaneous rate would be equal is at one specific instant during the reaction.
Correct answer: At one instant only- A. Straight line
- B. Parabola
- C. Curve
- D. Scattered graph
Explanation: Drawing a graph between concentration change with time give us a curve.
Correct answer: Curve- A. Inversely proportional to the square of the concentration
- B. Directly proportional to the cube of the concentration
- C. Inversely proportional to the concentration
- D. Directly proportional to the concentration
Explanation: The half-life of any order reaction is inversely proportional to the initial concentration raised to the power one less than the order of…
Correct answer: Inversely proportional to the square of the concentration- A. Rising
- B. Falling
- C. U shaped
- D. None of these options are correct
Explanation: The graph for the concentration data of the reactants will be a falling curve.
Correct answer: Falling- A. 24 minutes
- B. 72 minutes
- C. 120 minutes
- D. 48 minutes
Explanation: After one half-life, the concentration of N2O5 will be reduced to 50% of its original concentration.
Correct answer: 48 minutes- A. Negative catalysis
- B. Activation of catalyst
- C. Heterogeneous catalysis
- D. Autocatalysis
Explanation: Autocatalysis is the phenomenon in which a product formed in a reaction acts as a catalyst for the same reaction.
Correct answer: Autocatalysis- A. Concentration of reactants decrease
- B. Concentration of product decreases
- C. The order of reaction changes
- D. Temperature of the system changes
Explanation: The rate of a chemical reaction depends on the concentration of reactants.
Correct answer: Concentration of reactants decrease- A. Heat of reaction
- B. Rate of reaction
- C. Has no effect on the reaction
- D. Energy of activation
Explanation: The minimum energy with which molecules must be moving in order for an effective collision to result in a chemical reaction is known as…
Correct answer: Energy of activation- A. Chemical method
- B. Spectrometry
- C. Graphical method
- D. Differential method
Explanation: A general method employed to measure the rate of a reaction involves substances that can absorb radiations like UV, visible light, or…
Correct answer: Spectrometry- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The original Arrhenius equation is: k = Ae(-Ea/RT) Which can be rewritten as: log k = -Ea/RT log Ae, where Ea log Ae/R is a constant and T…
Correct answer: Option B- A. 2nd order reaction
- B. 1st order reaction
- C. Pseudo 1st order reaction
- D. 3rd order reaction
Explanation: Rate equation is mentioned and in case rate equation, especially order of reaction, is mentioned, then those are the only things to be…
Correct answer: 2nd order reaction- A. 1 min
- B. 2 min
- C. 0.693 min
- D. 4 min
Explanation: For first order reactions, half life is constant, which means that half life is independent of initial concentration.
Correct answer: 1 min- A. Always change to product
- B. Return back to reactants
- C. May return to reactants or proceed to form products
- D. Are of low energy
Explanation: The transition state is a high-energy state, and some amount of energy - the activation energy - must be added for the molecule to reach…
Correct answer: May return to reactants or proceed to form products- A. Theoretical term
- B. Experimental term
- C. Stoichiometric term
- D. Supposed term
Explanation: The actual yield is the quantity of a product that is obtained from a chemical reaction.
Correct answer: Experimental term- A. 1st order reaction
- B. 2nd order reaction
- C. Pseudo first order reaction
- D. Third order reaction
Explanation: A reaction which is not first-order reaction naturally but made first order by increasing or decreasing the concentration of one or the…
Correct answer: Pseudo first order reaction