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 0.25 min⁻¹. Find its half-life t½.

k = 0.25 min⁻¹
t½ = min
2.Easy
t (min)C (mol/L)t½​ = ?C0​/2

A first-order reaction has a rate constant of 0.02 min⁻¹. Find its half-life t½.

k = 0.02 min⁻¹
t½ = min
3.Medium
t (min)C (mol/L)10 minC = ?

A reaction with rate law −rA = k·CA² has k = 0.8 L/(mol·min) and starts at 2 mol/L. Find the concentration CA after 10 min.

k = 0.8 L/(mol·min)CA0 = 2 mol/Lt = 10 min
CA = mol/L
4.Medium
t (min)X (%)t = ?75%

A first-order reaction in a batch reactor has k = 0.15 min⁻¹. How long does it take to reach 75% conversion? Find t.

k = 0.15 min⁻¹X = 75 %
t = min
5.Hard
1/Tln kT = 25 °Cln 0.005ln A = ?Ea​ = 70 kJ/mol

A first-order reaction has a rate constant of 0.005 s⁻¹ at 25 °C and an activation energy of 70 kJ/mol. Find the pre-exponential factor A in the Arrhenius equation.

k = 0.005 s⁻¹T = 25 °CEa = 70 kJ/molR = 8.314 J/(mol·K)
A = s⁻¹
6.Hard
t (min)X (%)60 minX = ?

A first-order reaction has k = 0.01 min⁻¹ at 20 °C and an activation energy of 50 kJ/mol. The batch reactor is now run at 30 °C for 60 min. Find the conversion X reached.

k1 = 0.01 min⁻¹T1 = 20 °CEa = 50 kJ/molT2 = 30 °Ct = 60 minR = 8.314 J/(mol·K)
X = %

Answer key

  1. 1. t½ = 2.773 min
  2. 2. t½ = 34.66 min
  3. 3. CA = 0.1176 mol/L
  4. 4. t = 9.242 min
  5. 5. A = 9.186 × 10⁹ s⁻¹
  6. 6. X = 69.29 %

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