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)r0.4r = ?CB​ = 0.3 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 = 0.4 mol/L and CB = 0.3 mol/L.

r = k·CA·CB²k = 0.02 L²/(mol²·s)CA = 0.4 mol/LCB = 0.3 mol/L
r = mol/(L·s)
2.Easy
t (min)C (mol/L)15 minC = ?

A first-order reaction A → products has a rate constant of 0.025 min⁻¹. The initial concentration of A is 0.8 mol/L. Find the concentration CA after 15 min.

k = 0.025 min⁻¹CA0 = 0.8 mol/Lt = 15 min
CA = mol/L
3.Medium
t (min)X (%)t = ?80%

A first-order reaction in a batch reactor has k = 0.1 min⁻¹. How long does it take to reach 80% conversion? Find t.

k = 0.1 min⁻¹X = 80 %
t = min
4.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
5.Hard
CA0​ (mol/L)r (mol/(L·s))run 10.250.008run 20.50.032n = ?

Two experiments measure the initial rate of A → products. With CA0 = 0.25 mol/L the rate is 0.008 mol/(L·s); with CA0 = 0.5 mol/L it is 0.032 mol/(L·s). Find the reaction order n with respect to A.

CA0,1 = 0.25 mol/Lr1 = 0.008 mol/(L·s)CA0,2 = 0.5 mol/Lr2 = 0.032 mol/(L·s)
n =
6.Hard
CA0​ (mol/L)r (mol/(L·s))run 10.10.012run 20.30.0624n = ?

Two experiments measure the initial rate of A → products. With CA0 = 0.1 mol/L the rate is 0.012 mol/(L·s); with CA0 = 0.3 mol/L it is 0.0624 mol/(L·s). Find the reaction order n with respect to A.

CA0,1 = 0.1 mol/Lr1 = 0.012 mol/(L·s)CA0,2 = 0.3 mol/Lr2 = 0.0624 mol/(L·s)
n =

Answer key

  1. 1. r = 0.00072 mol/(L·s)
  2. 2. CA = 0.5498 mol/L
  3. 3. t = 16.09 min
  4. 4. t = 9.163 min
  5. 5. n = 2
  6. 6. n = 1.501

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