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

A first-order reaction A → products has a rate constant of 0.2 min⁻¹. The initial concentration of A is 1.5 mol/L. Find the concentration C_A after 10 min.

k = 0.2 min⁻¹C_A0 = 1.5 mol/Lt = 10 min

C_A = mol/L

2.Easy

The reaction A + B → C follows the rate law r = k·C_A², with k = 0.005 L/(mol·s). Find the reaction rate r when C_A = 2 mol/L and C_B = 0.5 mol/L.

r = k·C_A²k = 0.005 L/(mol·s)C_A = 2 mol/LC_B = 0.5 mol/L

r = mol/(L·s)

3.Medium

A second-order reaction (−r_A = k·C_A²) in a batch reactor has k = 0.8 L/(mol·min) and starts at 1 mol/L. How long does it take to reach 95% conversion? Find t.

k = 0.8 L/(mol·min)C_A0 = 1 mol/LX = 95 %

t = min

4.Medium

In a first-order reaction the concentration of A falls from 1 mol/L to 0.7 mol/L in 40 min. Find the rate constant k.

C_A0 = 1 mol/LC_A = 0.7 mol/Lt = 40 min

k = min⁻¹

5.Hard

The rate constant of a reaction is 0.002 min⁻¹ at 25 °C and 0.035 min⁻¹ at 65 °C. Find the activation energy E_a.

k₁ = 0.002 min⁻¹T₁ = 25 °Ck₂ = 0.035 min⁻¹T₂ = 65 °CR = 8.314 J/(mol·K)

E_a = kJ/mol

6.Hard

A first-order reaction has k = 0.002 min⁻¹ at 30 °C and an activation energy of 60 kJ/mol. The batch reactor is now run at 60 °C for 15 min. Find the conversion X reached.

k₁ = 0.002 min⁻¹T₁ = 30 °CE_a = 60 kJ/molT₂ = 60 °Ct = 15 minR = 8.314 J/(mol·K)

X = %

Answer key

1. C_A = 0.203 mol/L
2. r = 0.02 mol/(L·s)
3. t = 23.75 min
4. k = 0.008917 min⁻¹
5. E_a = 59.98 kJ/mol
6. X = 22.58 %

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