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​ = 5 min0.5

A first-order reaction has a half-life of 5 min. Find its rate constant k.

t½ = 5 min
k = min⁻¹
2.Easy
t (min)C (mol/L)20 minC = ?

A first-order reaction A → products has a rate constant of 0.02 min⁻¹. The initial concentration of A is 1.2 mol/L. Find the concentration CA after 20 min.

k = 0.02 min⁻¹CA0 = 1.2 mol/Lt = 20 min
CA = mol/L
3.Medium
t (min)X (%)t = ?80%

A first-order reaction in a batch reactor has k = 0.15 min⁻¹. How long does it take to reach 80% conversion? Find t.

k = 0.15 min⁻¹X = 80 %
t = min
4.Medium
t (min)C (mol/L)t½​ = ?C0​/2

A second-order reaction (−rA = k·CA²) has k = 0.25 L/(mol·min) and an initial concentration of 1 mol/L. Find its first half-life t½.

k = 0.25 L/(mol·min)CA0 = 1 mol/L
t½ = min
5.Hard
Tk25 °C0.00240 °C?

A reaction has a rate constant of 0.002 min⁻¹ at 25 °C and an activation energy of 100 kJ/mol. Find the rate constant k2 at 40 °C.

k1 = 0.002 min⁻¹T1 = 25 °CT2 = 40 °CEa = 100 kJ/molR = 8.314 J/(mol·K)
k2 = min⁻¹
6.Hard
Tk25 °C0.0240 °C?

A reaction has a rate constant of 0.02 min⁻¹ at 25 °C and an activation energy of 120 kJ/mol. Find the rate constant k2 at 40 °C.

k1 = 0.02 min⁻¹T1 = 25 °CT2 = 40 °CEa = 120 kJ/molR = 8.314 J/(mol·K)
k2 = min⁻¹

Answer key

  1. 1. k = 0.1386 min⁻¹
  2. 2. CA = 0.8044 mol/L
  3. 3. t = 10.73 min
  4. 4. t½ = 4 min
  5. 5. k2 = 0.01381 min⁻¹
  6. 6. k2 = 0.2033 min⁻¹

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