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 zero-order reaction A → products has a rate constant of 0.04 mol/(L·min). The initial concentration of A is 1 mol/L. Find the concentration C_A after 5 min.

k = 0.04 mol/(L·min)C_A0 = 1 mol/Lt = 5 min

C_A = mol/L

2.Easy

The reaction A + B → C follows the rate law r = k·C_A·C_B, with k = 0.02 L/(mol·s). Find the reaction rate r when C_A = 0.2 mol/L and C_B = 1.2 mol/L.

r = k·C_A·C_Bk = 0.02 L/(mol·s)C_A = 0.2 mol/LC_B = 1.2 mol/L

r = mol/(L·s)

3.Medium

A second-order reaction (−r_A = k·C_A²) has k = 1 L/(mol·min) and an initial concentration of 0.5 mol/L. Find its first half-life t_½.

k = 1 L/(mol·min)C_A0 = 0.5 mol/L

t_½ = min

4.Medium

A zero-order reaction has k = 0.02 mol/(L·min) and starts at 2 mol/L. How long does it take to reach 40% conversion? Find t.

k = 0.02 mol/(L·min)C_A0 = 2 mol/LX = 40 %

t = min

5.Hard

A reaction has a rate constant of 0.002 min⁻¹ at 25 °C and an activation energy of 55 kJ/mol. Find the rate constant k₂ at 35 °C.

k₁ = 0.002 min⁻¹T₁ = 25 °CT₂ = 35 °CE_a = 55 kJ/molR = 8.314 J/(mol·K)

k₂ = min⁻¹

6.Hard

Two experiments measure the initial rate of A → products. With C_A0 = 0.4 mol/L the rate is 0.002 mol/(L·s); with C_A0 = 0.8 mol/L it is 0.00566 mol/(L·s). Find the reaction order n with respect to A.

C_A0,1 = 0.4 mol/Lr₁ = 0.002 mol/(L·s)C_A0,2 = 0.8 mol/Lr₂ = 0.00566 mol/(L·s)

n =

Answer key

1. C_A = 0.8 mol/L
2. r = 0.0048 mol/(L·s)
3. t_½ = 2 min
4. t = 40 min
5. k₂ = 0.004109 min⁻¹
6. n = 1.501

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