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.

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1.Easy
t (min)C/C₀t½​ = 12 min0.5

A first-order reaction has a half-life of 12 min. Find its rate constant k.

t½ = 12 min
k = min⁻¹
2.Easy
t (min)C (mol/L)30 minC = ?

A first-order reaction A → products has a rate constant of 0.05 min⁻¹. The initial concentration of A is 0.8 mol/L. Find the concentration CA after 30 min.

k = 0.05 min⁻¹CA0 = 0.8 mol/Lt = 30 min
CA = mol/L
3.Medium
t (min)X (%)t = ?60%

A first-order reaction in a batch reactor has k = 0.01 min⁻¹. How long does it take to reach 60% conversion? Find t.

k = 0.01 min⁻¹X = 60 %
t = min
4.Medium
t (min)C (mol/L)5 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 5 min.

k = 0.25 L/(mol·min)CA0 = 0.5 mol/Lt = 5 min
CA = mol/L
5.Hard
Tk30 °C0.0570 °C1.27

The rate constant of a reaction is 0.05 min⁻¹ at 30 °C and 1.27 min⁻¹ at 70 °C. Find the activation energy Ea.

k1 = 0.05 min⁻¹T1 = 30 °Ck2 = 1.27 min⁻¹T2 = 70 °CR = 8.314 J/(mol·K)
Ea = kJ/mol
6.Hard
Tk40 °C0.00255 °C?

A reaction has a rate constant of 0.002 min⁻¹ at 40 °C and an activation energy of 50 kJ/mol. Find the rate constant k2 at 55 °C.

k1 = 0.002 min⁻¹T1 = 40 °CT2 = 55 °CEa = 50 kJ/molR = 8.314 J/(mol·K)
k2 = min⁻¹

Answer key

  1. 1. k = 0.05776 min⁻¹
  2. 2. CA = 0.1785 mol/L
  3. 3. t = 91.63 min
  4. 4. CA = 0.3077 mol/L
  5. 5. Ea = 69.94 kJ/mol
  6. 6. k2 = 0.004812 min⁻¹

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