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)20 minC = ?

A first-order reaction A → products has a rate constant of 0.08 min⁻¹. The initial concentration of A is 0.5 mol/L. Find the concentration CA after 20 min.

k = 0.08 min⁻¹CA0 = 0.5 mol/Lt = 20 min
CA = mol/L
2.Easy
t (min)C (mol/L)t½​ = ?C0​/2

A first-order reaction has a rate constant of 0.01 min⁻¹. Find its half-life t½.

k = 0.01 min⁻¹
t½ = min
3.Medium
t (min)X (%)t = ?80%

A zero-order reaction has k = 0.02 mol/(L·min) and starts at 1.2 mol/L. How long does it take to reach 80% conversion? Find t.

k = 0.02 mol/(L·min)CA0 = 1.2 mol/LX = 80 %
t = min
4.Medium
t (min)C (mol/L)20 minC = ?

A reaction with rate law −rA = k·CA² has k = 0.2 L/(mol·min) and starts at 1 mol/L. Find the concentration CA after 20 min.

k = 0.2 L/(mol·min)CA0 = 1 mol/Lt = 20 min
CA = mol/L
5.Hard
Tk20 °C0.00560 °C1.85

The rate constant of a reaction is 0.005 min⁻¹ at 20 °C and 1.85 min⁻¹ at 60 °C. Find the activation energy Ea.

k1 = 0.005 min⁻¹T1 = 20 °Ck2 = 1.85 min⁻¹T2 = 60 °CR = 8.314 J/(mol·K)
Ea = kJ/mol
6.Hard
Tk40 °C0.0150 °C0.0192

The rate constant of a reaction is 0.01 min⁻¹ at 40 °C and 0.0192 min⁻¹ at 50 °C. Find the activation energy Ea.

k1 = 0.01 min⁻¹T1 = 40 °Ck2 = 0.0192 min⁻¹T2 = 50 °CR = 8.314 J/(mol·K)
Ea = kJ/mol

Answer key

  1. 1. CA = 0.1009 mol/L
  2. 2. t½ = 69.31 min
  3. 3. t = 48 min
  4. 4. CA = 0.2 mol/L
  5. 5. Ea = 120 kJ/mol
  6. 6. Ea = 54.88 kJ/mol

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