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/C₀ (%)60 min?

A first-order reaction has a half-life of 30 min. What percentage f of the reactant is still left after 60 min?

t½ = 30 mint = 60 min
f = %
2.Easy
t (min)C (mol/L)60 minC = ?

A zero-order reaction A → products has a rate constant of 0.01 mol/(L·min). The initial concentration of A is 2 mol/L. Find the concentration CA after 60 min.

k = 0.01 mol/(L·min)CA0 = 2 mol/Lt = 60 min
CA = mol/L
3.Medium
t (min)X (%)t = ?50%

A zero-order reaction has k = 0.01 mol/(L·min) and starts at 2 mol/L. How long does it take to reach 50% conversion? Find t.

k = 0.01 mol/(L·min)CA0 = 2 mol/LX = 50 %
t = min
4.Medium
t (min)C (mol/L)t½​ = ?C0​/2

A second-order reaction (−rA = k·CA²) has k = 0.05 L/(mol·min) and an initial concentration of 2 mol/L. Find its first half-life t½.

k = 0.05 L/(mol·min)CA0 = 2 mol/L
t½ = min
5.Hard
Tk25 °Ck1​?10·k1​

A reaction has an activation energy of 80 kJ/mol. At 25 °C it is too slow. To what temperature T2 (in °C) must it be heated to make it 10 times faster?

Ea = 80 kJ/molT1 = 25 °Ck2/k1 = 10R = 8.314 J/(mol·K)
T2 = °C
6.Hard
1/Tln kT = 80 °Cln 0.005ln A = ?Ea​ = 90 kJ/mol

A first-order reaction has a rate constant of 0.005 s⁻¹ at 80 °C and an activation energy of 90 kJ/mol. Find the pre-exponential factor A in the Arrhenius equation.

k = 0.005 s⁻¹T = 80 °CEa = 90 kJ/molR = 8.314 J/(mol·K)
A = s⁻¹

Answer key

  1. 1. f = 25 %
  2. 2. CA = 1.4 mol/L
  3. 3. t = 100 min
  4. 4. t½ = 10 min
  5. 5. T2 = 47.91 °C
  6. 6. A = 1.027 × 10¹¹ s⁻¹

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