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
CA​ (mol/L)r2r = ?CB​ = 1 mol/L

The reaction A + B → C follows the rate law r = k·CA²·CB, with k = 0.2 L²/(mol²·s). Find the reaction rate r when CA = 2 mol/L and CB = 1 mol/L.

r = k·CA²·CBk = 0.2 L²/(mol²·s)CA = 2 mol/LCB = 1 mol/L
r = mol/(L·s)
2.Easy
t (min)C/C₀t½​ = 10 min0.5

A first-order reaction has a half-life of 10 min. Find its rate constant k.

t½ = 10 min
k = min⁻¹
3.Medium
t (min)X (%)t = ?90%

A first-order reaction in a batch reactor has k = 0.15 min⁻¹. How long does it take to reach 90% conversion? Find t.

k = 0.15 min⁻¹X = 90 %
t = min
4.Medium
t (min)X (%)t = ?75%

A first-order reaction in a batch reactor has k = 0.1 min⁻¹. How long does it take to reach 75% conversion? Find t.

k = 0.1 min⁻¹X = 75 %
t = min
5.Hard
Tk40 °C0.00265 °C?

A reaction has a rate constant of 0.002 min⁻¹ at 40 °C and an activation energy of 70 kJ/mol. Find the rate constant k2 at 65 °C.

k1 = 0.002 min⁻¹T1 = 40 °CT2 = 65 °CEa = 70 kJ/molR = 8.314 J/(mol·K)
k2 = min⁻¹
6.Hard
CA0​ (mol/L)r (mol/(L·s))run 10.250.01run 20.50.0283n = ?

Two experiments measure the initial rate of A → products. With CA0 = 0.25 mol/L the rate is 0.01 mol/(L·s); with CA0 = 0.5 mol/L it is 0.0283 mol/(L·s). Find the reaction order n with respect to A.

CA0,1 = 0.25 mol/Lr1 = 0.01 mol/(L·s)CA0,2 = 0.5 mol/Lr2 = 0.0283 mol/(L·s)
n =

Answer key

  1. 1. r = 0.8 mol/(L·s)
  2. 2. k = 0.06931 min⁻¹
  3. 3. t = 15.35 min
  4. 4. t = 13.86 min
  5. 5. k2 = 0.0146 min⁻¹
  6. 6. n = 1.501

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