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
t (min)C/C₀t½​ = 4 min0.5

A first-order reaction has a half-life of 4 min. Find its rate constant k.

t½ = 4 min
k = min⁻¹
3.Medium
t (min)X (%)t = ?80%

A first-order reaction in a batch reactor has k = 0.02 min⁻¹. How long does it take to reach 80% conversion? Find t.

k = 0.02 min⁻¹X = 80 %
t = min
4.Medium
t (min)C (mol/L)t½​ = ?C0​/2

A second-order reaction (−rA = k·CA²) has k = 0.2 L/(mol·min) and an initial concentration of 2 mol/L. Find its first half-life t½.

k = 0.2 L/(mol·min)CA0 = 2 mol/L
t½ = min
5.Hard
1/Tln kT = 25 °Cln 0.005ln A = ?Ea​ = 75 kJ/mol

A first-order reaction has a rate constant of 0.005 s⁻¹ at 25 °C and an activation energy of 75 kJ/mol. Find the pre-exponential factor A in the Arrhenius equation.

k = 0.005 s⁻¹T = 25 °CEa = 75 kJ/molR = 8.314 J/(mol·K)
A = s⁻¹
6.Hard
Tk40 °C0.00570 °C?

A reaction has a rate constant of 0.005 min⁻¹ at 40 °C and an activation energy of 50 kJ/mol. Find the rate constant k2 at 70 °C.

k1 = 0.005 min⁻¹T1 = 40 °CT2 = 70 °CEa = 50 kJ/molR = 8.314 J/(mol·K)
k2 = min⁻¹

Answer key

  1. 1. t½ = 8.664 min
  2. 2. k = 0.1733 min⁻¹
  3. 3. t = 80.47 min
  4. 4. t½ = 2.5 min
  5. 5. A = 6.905 × 10¹⁰ s⁻¹
  6. 6. k2 = 0.0268 min⁻¹

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