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​ = 40 min0.5

A first-order reaction has a half-life of 40 min. Find its rate constant k.

t½ = 40 min
k = min⁻¹
2.Easy
t (min)C (mol/L)15 minC = ?

A first-order reaction A → products has a rate constant of 0.08 min⁻¹. The initial concentration of A is 0.8 mol/L. Find the concentration CA after 15 min.

k = 0.08 min⁻¹CA0 = 0.8 mol/Lt = 15 min
CA = mol/L
3.Medium
t (min)X (%)t = ?75%

A second-order reaction (−rA = k·CA²) in a batch reactor has k = 0.05 L/(mol·min) and starts at 2 mol/L. How long does it take to reach 75% conversion? Find t.

k = 0.05 L/(mol·min)CA0 = 2 mol/LX = 75 %
t = min
4.Medium
t (min)X (%)t = ?90%

A first-order reaction in a batch reactor has k = 0.05 min⁻¹. How long does it take to reach 90% conversion? Find t.

k = 0.05 min⁻¹X = 90 %
t = min
5.Hard
1/Tln kT = 25 °Cln 0.01ln A = ?Ea​ = 75 kJ/mol

A first-order reaction has a rate constant of 0.01 s⁻¹ at 25 °C and an activation energy of 75 kJ/mol. Find the pre-exponential factor A in the Arrhenius equation.

k = 0.01 s⁻¹T = 25 °CEa = 75 kJ/molR = 8.314 J/(mol·K)
A = s⁻¹
6.Hard
Tk40 °C0.0565 °C0.275

The rate constant of a reaction is 0.05 min⁻¹ at 40 °C and 0.275 min⁻¹ at 65 °C. Find the activation energy Ea.

k1 = 0.05 min⁻¹T1 = 40 °Ck2 = 0.275 min⁻¹T2 = 65 °CR = 8.314 J/(mol·K)
Ea = kJ/mol

Answer key

  1. 1. k = 0.01733 min⁻¹
  2. 2. CA = 0.241 mol/L
  3. 3. t = 30 min
  4. 4. t = 46.05 min
  5. 5. A = 1.381 × 10¹¹ s⁻¹
  6. 6. Ea = 60.03 kJ/mol

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