Chemical equilibrium worksheet with answers

Free printable Chemical equilibrium worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
N2​O4​0.2mol/L⇌2NO2​0.2mol/LKc​ = ?

For the reaction N2O4 ⇌ 2NO2, the equilibrium concentrations are [N2O4] = 0.2 mol/L, [NO2] = 0.2 mol/L. Find the equilibrium constant Kc.

[N2O4] = 0.2[NO2] = 0.2
Kc =
2.Easy
CO0.08mol/L+H2​O0.1mol/L⇌CO2​0.1mol/L+H2​0.12mol/LKc​ = ?

For the reaction CO + H2O ⇌ CO2 + H2, the equilibrium concentrations are [CO] = 0.08 mol/L, [H2O] = 0.1 mol/L, [CO2] = 0.1 mol/L, [H2] = 0.12 mol/L. Find the equilibrium constant Kc.

[CO] = 0.08[H2O] = 0.1[CO2] = 0.1[H2] = 0.12
Kc =
3.Medium
H2​I2​HII0.40.40C−x−x+2xE0.4 − x0.4 − x2x

0.4 mol/L of H₂ and 0.4 mol/L of I₂ are put in a container and react: H₂ + I₂ ⇌ 2HI, with Kc = 16. Find the equilibrium concentration [H2].

[H₂]₀ = [I₂]₀ = 0.4 mol/LKc = 16
[H2] = mol/L
4.Medium
H2​I2​HII0.10.10C−x−x+2xE0.1 − x0.1 − x2x

0.1 mol/L of H₂ and 0.1 mol/L of I₂ are put in a container and react: H₂ + I₂ ⇌ 2HI, with Kc = 9. Find the equilibrium concentration [H2].

[H₂]₀ = [I₂]₀ = 0.1 mol/LKc = 9
[H2] = mol/L
5.Hard
PCl5​PCl3​Cl2​I100C−x+x+xE1 − xxx

PCl₅ decomposes: PCl₅ ⇌ PCl₃ + Cl₂, with Kc = 0.04 at the reaction temperature. A container starts with 1 mol/L of PCl₅ only. Find the equilibrium concentration [Cl2].

[PCl₅]₀ = 1 mol/LKc = 0.04
[Cl2] = mol/L
6.Hard
PCl5​PCl3​Cl2​I0.800C−x+x+xE0.8 − xxx

PCl₅ decomposes: PCl₅ ⇌ PCl₃ + Cl₂, with Kc = 0.05 at the reaction temperature. A container starts with 0.8 mol/L of PCl₅ only. Find the equilibrium concentration [Cl2].

[PCl₅]₀ = 0.8 mol/LKc = 0.05
[Cl2] = mol/L

Answer key

  1. 1. Kc = 0.2
  2. 2. Kc = 1.5
  3. 3. [H2] = 0.1333 mol/L
  4. 4. [H2] = 0.04 mol/L
  5. 5. [Cl2] = 0.181 mol/L
  6. 6. [Cl2] = 0.1766 mol/L

Full step-by-step solutions: practise this topic on examproblems.com.