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)10 minC = ?

A zero-order reaction A → products has a rate constant of 0.02 mol/(L·min). The initial concentration of A is 1.2 mol/L. Find the concentration CA after 10 min.

k = 0.02 mol/(L·min)CA0 = 1.2 mol/Lt = 10 min
CA = mol/L
2.Easy
t (min)C/C₀t½​ = 3 min0.5

A first-order reaction has a half-life of 3 min. Find its rate constant k.

t½ = 3 min
k = min⁻¹
3.Medium
t (min)C (mol/L)10 minC = ?

A reaction with rate law −rA = k·CA² has k = 0.4 L/(mol·min) and starts at 1 mol/L. Find the concentration CA after 10 min.

k = 0.4 L/(mol·min)CA0 = 1 mol/Lt = 10 min
CA = mol/L
4.Medium
t (min)X (%)t = ?75%

A first-order reaction in a batch reactor has k = 0.3 min⁻¹. How long does it take to reach 75% conversion? Find t.

k = 0.3 min⁻¹X = 75 %
t = min
5.Hard
1/Tln kT = 60 °Cln 0.1ln A = ?Ea​ = 70 kJ/mol

A first-order reaction has a rate constant of 0.1 s⁻¹ at 60 °C and an activation energy of 70 kJ/mol. Find the pre-exponential factor A in the Arrhenius equation.

k = 0.1 s⁻¹T = 60 °CEa = 70 kJ/molR = 8.314 J/(mol·K)
A = s⁻¹
6.Hard
Tk35 °C0.145 °C0.302

The rate constant of a reaction is 0.1 min⁻¹ at 35 °C and 0.302 min⁻¹ at 45 °C. Find the activation energy Ea.

k1 = 0.1 min⁻¹T1 = 35 °Ck2 = 0.302 min⁻¹T2 = 45 °CR = 8.314 J/(mol·K)
Ea = kJ/mol

Answer key

  1. 1. CA = 1 mol/L
  2. 2. k = 0.231 min⁻¹
  3. 3. CA = 0.2 mol/L
  4. 4. t = 4.621 min
  5. 5. A = 9.456 × 10⁹ s⁻¹
  6. 6. Ea = 90.09 kJ/mol

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