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)90 minC = ?

A first-order reaction A → products has a rate constant of 0.02 min⁻¹. The initial concentration of A is 0.5 mol/L. Find the concentration CA after 90 min.

k = 0.02 min⁻¹CA0 = 0.5 mol/Lt = 90 min
CA = mol/L
2.Easy
t (min)C (mol/L)10 minC = ?

A first-order reaction A → products has a rate constant of 0.2 min⁻¹. The initial concentration of A is 0.5 mol/L. Find the concentration CA after 10 min.

k = 0.2 min⁻¹CA0 = 0.5 mol/Lt = 10 min
CA = mol/L
3.Medium
t (min)C (mol/L)5 minC = ?

A reaction with rate law −rA = k·CA² has k = 0.05 L/(mol·min) and starts at 0.5 mol/L. Find the concentration CA after 5 min.

k = 0.05 L/(mol·min)CA0 = 0.5 mol/Lt = 5 min
CA = mol/L
4.Medium
t (min)X (%)t = ?95%

A first-order reaction in a batch reactor has k = 0.08 min⁻¹. How long does it take to reach 95% conversion? Find t.

k = 0.08 min⁻¹X = 95 %
t = min
5.Hard
Tk35 °C0.160 °C?

A reaction has a rate constant of 0.1 min⁻¹ at 35 °C and an activation energy of 100 kJ/mol. Find the rate constant k2 at 60 °C.

k1 = 0.1 min⁻¹T1 = 35 °CT2 = 60 °CEa = 100 kJ/molR = 8.314 J/(mol·K)
k2 = min⁻¹
6.Hard
Tk25 °C0.00535 °C0.0143

The rate constant of a reaction is 0.005 min⁻¹ at 25 °C and 0.0143 min⁻¹ at 35 °C. Find the activation energy Ea.

k1 = 0.005 min⁻¹T1 = 25 °Ck2 = 0.0143 min⁻¹T2 = 35 °CR = 8.314 J/(mol·K)
Ea = kJ/mol

Answer key

  1. 1. CA = 0.08265 mol/L
  2. 2. CA = 0.06767 mol/L
  3. 3. CA = 0.4444 mol/L
  4. 4. t = 37.45 min
  5. 5. k2 = 1.871 min⁻¹
  6. 6. Ea = 80.27 kJ/mol

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