Worksheet: The Arrhenius Equation

In this worksheet, we will practice using the Arrhenius equation to calculate reaction activation energies and frequency (preexponential) factors.

Q1:

When the temperature increases from 30C to 37C, the rate of an enzyme-catalyzed reaction increases by a factor of 1.47. Calculate, to 3 significant figures, the activation energy for this reaction.

Q2:

A sample of hydrogen peroxide decomposes with a rate constant of 2.20×10 s−1 at 80C and 5.65×10 s−1 at 35C. Calculate, to 3 significant figures, the activation energy for this reaction.

Q3:

Butene can decompose to two molecules of ethene when heated. The rate constant for the decomposition reaction at 325C is 6.10×10 s−1 and the activation energy is 261.0 kJ/mol. Estimate the frequency (preexponential) factor for the reaction, to 2 significant figures.

  • A 1 . 2 × 1 0 s−1
  • B 6 . 3 × 1 0 s−1
  • C 3 . 0 × 1 0 s−1
  • D 3 . 8 × 1 0 s−1
  • E 5 . 4 × 1 0 s−1

Q4:

The rate constant for a reaction, 𝑘, was measured over a range of reaction temperatures, 𝑇. The data were plotted on a graph of ln𝑘 against 1𝑇. What is the frequency (preexponential) factor for the reaction in terms of the gradient of the plot 𝑚 and the 𝑦-intercept 𝑐?

  • A e
  • B l n ( 𝑚 )
  • C l n ( 𝑐 )
  • D e
  • E e

Q5:

Hydrolysis of the sugar sucrose (CHO122211) produces glucose and fructose. This first-order reaction has a rate constant of 2.10×10s at 27C and 8.50×10s at 37C.

Calculate the activation energy for this reaction, to three significant figures.

Calculate the rate constant for this reaction at 47C, to two significant figures.

  • A 3 . 2 × 1 0 s−1
  • B 1 . 1 × 1 0 s−1
  • C 4 . 6 × 1 0 s−1
  • D 6 . 3 × 1 0 s−1
  • E 2 . 5 × 1 0 s−1

Estimate, to two significant figures, the time needed for the concentration of a 0.150 M sucrose solution to decrease to 1.65×10 M at 20C.

  • A 1 . 9 × 1 0 days
  • B 2 . 1 × 1 0 days
  • C 7 . 6 × 1 0 days
  • D 5 . 0 × 1 0 days
  • E 9 . 2 × 1 0 days

Q6:

A sample of dinitrogen pentoxide (NO)25 decomposes with a rate constant of 1.66 L/mol⋅s at 650 K and 7.39 L/mol⋅s at 700 K. Calculate, to 3 significant figures, the activation energy for this reaction.

Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy.