The rate of a chemical reaction is defined as the change in concentration of a reactant or product per unit time. If the concentration of a reactant decreases from 0.8 M to 0.2 M in 3 seconds, what is the average rate of reaction?
Practice 2easy
For a first-order reaction, the integrated rate law is given by ln[A] = ln[A]₀ - kt. If the half-life of a first-order reaction is 10 minutes, what will be the half-life if the initial concentration is doubled?
Practice 3easy
The activation energy (Eₐ) of a reaction is the minimum energy required for reactants to form products. How does increasing the temperature of a reaction affect the number of collisions with energy ≥ Eₐ?
Practice 4easy
A catalyst is a substance that increases the rate of reaction by lowering the activation energy. Which of the following statements about catalysts is correct?
Practice 5easy
For a zero-order reaction, the integrated rate law is [A] = [A]₀ - kt. If a zero-order reaction has a rate constant of 0.05 M/s and initial concentration of 2 M, how long will it take for the concentration to become zero?
Practice 6medium
The rate constant for a first-order reaction is 0.693 min⁻¹. What is the half-life of this reaction?
Practice 7medium
If the concentration of a reactant decreases from 1.0 M to 0.25 M in 20 minutes for a zero-order reaction, what is the rate constant?
Practice 8medium
The activation energy of a reaction is 50 kJ/mol. If the temperature is increased from 300 K to 310 K, by what factor does the rate constant increase? (R = 8.314 J mol⁻¹ K⁻¹)
Practice 9medium
For a reaction with rate law: rate = k[A]²[B], what is the overall order of the reaction?
Practice 10medium
A second-order reaction has a rate constant of 0.5 L mol⁻¹ s⁻¹. If the initial concentration is 2 M, what is the time required for the concentration to drop to 0.5 M?
Practice 11medium
Which of the following correctly relates to the integrated rate law for a first-order reaction?
Practice 12medium
A catalyst increases the rate of a reaction by lowering which of the following?
Practice 13medium
For the reaction 2A + B → C, the rate law is: rate = k[A][B]². If [A] is doubled and [B] is halved, the rate changes by a factor of:
Practice 14hard
For a first-order reaction, if the rate constant k = 0.693 min⁻¹, what is the half-life of the reaction?
Practice 15hard
A reaction has an activation energy of 50 kJ/mol. If the rate constant doubles when temperature increases from 300 K to 310 K, which statement is correct?
Practice 16hard
For the reaction 2A + B → C, the rate law is determined to be: Rate = k[A]²[B]. If [A] is doubled and [B] is halved, by what factor does the reaction rate change?