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 0.08 min⁻¹. Find its half-life t½.

k = 0.08 min⁻¹
t½ = min
2.Easy
CA​ (mol/L)r2r = ?CB​ = 0.6 mol/L

The reaction A + B → C follows the rate law r = k·CA·CB², with k = 0.02 L²/(mol²·s). Find the reaction rate r when CA = 2 mol/L and CB = 0.6 mol/L.

r = k·CA·CB²k = 0.02 L²/(mol²·s)CA = 2 mol/LCB = 0.6 mol/L
r = mol/(L·s)
3.Medium
t (min)X (%)t = ?60%

A first-order reaction in a batch reactor has k = 0.1 min⁻¹. How long does it take to reach 60% conversion? Find t.

k = 0.1 min⁻¹X = 60 %
t = min
4.Medium
t (min)X (%)t = ?60%

A first-order reaction in a batch reactor has k = 0.08 min⁻¹. How long does it take to reach 60% conversion? Find t.

k = 0.08 min⁻¹X = 60 %
t = min
5.Hard
Tk20 °C0.0230 °C?

A reaction has a rate constant of 0.02 min⁻¹ at 20 °C and an activation energy of 90 kJ/mol. Find the rate constant k2 at 30 °C.

k1 = 0.02 min⁻¹T1 = 20 °CT2 = 30 °CEa = 90 kJ/molR = 8.314 J/(mol·K)
k2 = min⁻¹
6.Hard
Tk20 °C0.130 °C0.172

The rate constant of a reaction is 0.1 min⁻¹ at 20 °C and 0.172 min⁻¹ at 30 °C. Find the activation energy Ea.

k1 = 0.1 min⁻¹T1 = 20 °Ck2 = 0.172 min⁻¹T2 = 30 °CR = 8.314 J/(mol·K)
Ea = kJ/mol

Answer key

  1. 1. t½ = 8.664 min
  2. 2. r = 0.0144 mol/(L·s)
  3. 3. t = 9.163 min
  4. 4. t = 11.45 min
  5. 5. k2 = 0.06762 min⁻¹
  6. 6. Ea = 40.07 kJ/mol

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