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​ = 20 min0.5

A first-order reaction has a half-life of 20 min. Find its rate constant k.

t½ = 20 min
k = min⁻¹
2.Easy
t (min)C (mol/L)t½​ = ?C0​/2

A first-order reaction has a rate constant of 0.1 min⁻¹. Find its half-life t½.

k = 0.1 min⁻¹
t½ = min
3.Medium
t (min)C (mol/L)30 min0.35

In a first-order reaction the concentration of A falls from 0.5 mol/L to 0.35 mol/L in 30 min. Find the rate constant k.

CA0 = 0.5 mol/LCA = 0.35 mol/Lt = 30 min
k = min⁻¹
4.Medium
t (min)X (%)t = ?99%

A first-order reaction in a batch reactor has k = 0.1 min⁻¹. How long does it take to reach 99% conversion? Find t.

k = 0.1 min⁻¹X = 99 %
t = min
5.Hard
Tk20 °C0.0535 °C?

A reaction has a rate constant of 0.05 min⁻¹ at 20 °C and an activation energy of 90 kJ/mol. Find the rate constant k2 at 35 °C.

k1 = 0.05 min⁻¹T1 = 20 °CT2 = 35 °CEa = 90 kJ/molR = 8.314 J/(mol·K)
k2 = min⁻¹
6.Hard
Tk20 °C0.00540 °C0.116

The rate constant of a reaction is 0.005 min⁻¹ at 20 °C and 0.116 min⁻¹ at 40 °C. Find the activation energy Ea.

k1 = 0.005 min⁻¹T1 = 20 °Ck2 = 0.116 min⁻¹T2 = 40 °CR = 8.314 J/(mol·K)
Ea = kJ/mol

Answer key

  1. 1. k = 0.03466 min⁻¹
  2. 2. t½ = 6.931 min
  3. 3. k = 0.01189 min⁻¹
  4. 4. t = 46.05 min
  5. 5. k2 = 0.3017 min⁻¹
  6. 6. Ea = 120 kJ/mol

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