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 (mol/L)15 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 15 min.

k = 0.05 min⁻¹CA0 = 0.8 mol/Lt = 15 min
CA = mol/L
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)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)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
Tk25 °C0.0550 °C0.278

The rate constant of a reaction is 0.05 min⁻¹ at 25 °C and 0.278 min⁻¹ at 50 °C. Find the activation energy Ea.

k1 = 0.05 min⁻¹T1 = 25 °Ck2 = 0.278 min⁻¹T2 = 50 °CR = 8.314 J/(mol·K)
Ea = kJ/mol
6.Hard
Tk30 °C0.0240 °C0.0551

The rate constant of a reaction is 0.02 min⁻¹ at 30 °C and 0.0551 min⁻¹ at 40 °C. Find the activation energy Ea.

k1 = 0.02 min⁻¹T1 = 30 °Ck2 = 0.0551 min⁻¹T2 = 40 °CR = 8.314 J/(mol·K)
Ea = kJ/mol

Answer key

  1. 1. CA = 0.3779 mol/L
  2. 2. t½ = 27.73 min
  3. 3. t = 91.63 min
  4. 4. t = 46.05 min
  5. 5. Ea = 54.97 kJ/mol
  6. 6. Ea = 79.98 kJ/mol

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