Reaction kinetics worksheet with answers

Free printable Reaction kinetics worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
t (min)C (mol/L)t½​ = ?C0​/2

A first-order reaction has a rate constant of 0.15 min⁻¹. Find its half-life t½.

k = 0.15 min⁻¹
t½ = min
2.Easy
t (min)C/C₀ (%)100 min?

A first-order reaction has a half-life of 20 min. What percentage f of the reactant is still left after 100 min?

t½ = 20 mint = 100 min
f = %
3.Medium
t (min)X (%)t = ?95%

A first-order reaction in a batch reactor has k = 0.01 min⁻¹. How long does it take to reach 95% conversion? Find t.

k = 0.01 min⁻¹X = 95 %
t = min
4.Medium
t (min)X (%)t = ?50%

A zero-order reaction has k = 0.02 mol/(L·min) and starts at 1 mol/L. How long does it take to reach 50% conversion? Find t.

k = 0.02 mol/(L·min)CA0 = 1 mol/LX = 50 %
t = min
5.Hard
Tk30 °C0.00550 °C0.0952

The rate constant of a reaction is 0.005 min⁻¹ at 30 °C and 0.0952 min⁻¹ at 50 °C. Find the activation energy Ea.

k1 = 0.005 min⁻¹T1 = 30 °Ck2 = 0.0952 min⁻¹T2 = 50 °CR = 8.314 J/(mol·K)
Ea = kJ/mol
6.Hard
CA0​ (mol/L)r (mol/(L·s))run 10.50.012run 210.024n = ?

Two experiments measure the initial rate of A → products. With CA0 = 0.5 mol/L the rate is 0.012 mol/(L·s); with CA0 = 1 mol/L it is 0.024 mol/(L·s). Find the reaction order n with respect to A.

CA0,1 = 0.5 mol/Lr1 = 0.012 mol/(L·s)CA0,2 = 1 mol/Lr2 = 0.024 mol/(L·s)
n =

Answer key

  1. 1. t½ = 4.621 min
  2. 2. f = 3.125 %
  3. 3. t = 299.6 min
  4. 4. t = 25 min
  5. 5. Ea = 120 kJ/mol
  6. 6. n = 1

Full step-by-step solutions: practise this topic on examproblems.com.