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/C₀t½​ = 15 min0.5

A first-order reaction has a half-life of 15 min. Find its rate constant k.

t½ = 15 min
k = min⁻¹
2.Easy
t (min)C (mol/L)t½​ = ?C0​/2

A first-order reaction has a rate constant of 0.025 min⁻¹. Find its half-life t½.

k = 0.025 min⁻¹
t½ = min
3.Medium
t (min)C (mol/L)30 minC = ?

A reaction with rate law −rA = k·CA² has k = 0.25 L/(mol·min) and starts at 0.5 mol/L. Find the concentration CA after 30 min.

k = 0.25 L/(mol·min)CA0 = 0.5 mol/Lt = 30 min
CA = mol/L
4.Medium
t (min)X (%)t = ?80%

A second-order reaction (−rA = k·CA²) in a batch reactor has k = 0.1 L/(mol·min) and starts at 1 mol/L. How long does it take to reach 80% conversion? Find t.

k = 0.1 L/(mol·min)CA0 = 1 mol/LX = 80 %
t = min
5.Hard
1/Tln kT = 40 °Cln 0.05ln A = ?Ea​ = 60 kJ/mol

A first-order reaction has a rate constant of 0.05 s⁻¹ at 40 °C and an activation energy of 60 kJ/mol. Find the pre-exponential factor A in the Arrhenius equation.

k = 0.05 s⁻¹T = 40 °CEa = 60 kJ/molR = 8.314 J/(mol·K)
A = s⁻¹
6.Hard
CA0​ (mol/L)r (mol/(L·s))run 10.20.005run 20.40.04n = ?

Two experiments measure the initial rate of A → products. With CA0 = 0.2 mol/L the rate is 0.005 mol/(L·s); with CA0 = 0.4 mol/L it is 0.04 mol/(L·s). Find the reaction order n with respect to A.

CA0,1 = 0.2 mol/Lr1 = 0.005 mol/(L·s)CA0,2 = 0.4 mol/Lr2 = 0.04 mol/(L·s)
n =

Answer key

  1. 1. k = 0.04621 min⁻¹
  2. 2. t½ = 27.73 min
  3. 3. CA = 0.1053 mol/L
  4. 4. t = 40 min
  5. 5. A = 5.1 × 10⁸ s⁻¹
  6. 6. n = 3

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