Worksheet: The Arrhenius Equation

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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 to , 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 s⁻¹ at and s⁻¹ at . 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 is s⁻¹ and the activation energy is 261.0 kJ/mol. Estimate the frequency (preexponential) factor for the reaction, to 2 significant figures.

A s⁻¹
B s⁻¹
C s⁻¹
D s⁻¹
E s⁻¹

Q4:

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

Q5:

Hydrolysis of the sugar sucrose () produces glucose and fructose. This first-order reaction has a rate constant of at and at .

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

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

A s⁻¹
B s⁻¹
C s⁻¹
D s⁻¹
E s⁻¹

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

A days
B days
C days
D days
E days

Q6:

A sample of dinitrogen pentoxide 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.