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)t½​ = ?C0​/2

A first-order reaction has a rate constant of 0.05 min⁻¹. Find its half-life t½.

k = 0.05 min⁻¹
t½ = min
2.Easy
t (min)C (mol/L)40 minC = ?

A first-order reaction A → products has a rate constant of 0.01 min⁻¹. The initial concentration of A is 0.8 mol/L. Find the concentration CA after 40 min.

k = 0.01 min⁻¹CA0 = 0.8 mol/Lt = 40 min
CA = mol/L
3.Medium
t (min)C (mol/L)t½​ = ?C0​/2

A second-order reaction (−rA = k·CA²) has k = 0.02 L/(mol·min) and an initial concentration of 2 mol/L. Find its first half-life t½.

k = 0.02 L/(mol·min)CA0 = 2 mol/L
t½ = min
4.Medium
t (min)X (%)t = ?30%

A zero-order reaction has k = 0.04 mol/(L·min) and starts at 1.5 mol/L. How long does it take to reach 30% conversion? Find t.

k = 0.04 mol/(L·min)CA0 = 1.5 mol/LX = 30 %
t = min
5.Hard
Tk20 °C0.00530 °C0.0138

The rate constant of a reaction is 0.005 min⁻¹ at 20 °C and 0.0138 min⁻¹ at 30 °C. Find the activation energy Ea.

k1 = 0.005 min⁻¹T1 = 20 °Ck2 = 0.0138 min⁻¹T2 = 30 °CR = 8.314 J/(mol·K)
Ea = kJ/mol
6.Hard
Tk40 °C0.0560 °C?

A reaction has a rate constant of 0.05 min⁻¹ at 40 °C and an activation energy of 60 kJ/mol. Find the rate constant k2 at 60 °C.

k1 = 0.05 min⁻¹T1 = 40 °CT2 = 60 °CEa = 60 kJ/molR = 8.314 J/(mol·K)
k2 = min⁻¹

Answer key

  1. 1. t½ = 13.86 min
  2. 2. CA = 0.5363 mol/L
  3. 3. t½ = 25 min
  4. 4. t = 11.25 min
  5. 5. Ea = 75.01 kJ/mol
  6. 6. k2 = 0.1994 min⁻¹

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