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 worksheet Practise 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

For the reaction N₂O₄ ⇌ 2NO₂, the equilibrium concentrations are [N₂O₄] = 0.4 mol/L, [NO₂] = 0.3 mol/L. Find the equilibrium constant K_c.

[N₂O₄] = 0.4[NO₂] = 0.3

K_c =

2.Easy

For the reaction H₂ + I₂ ⇌ 2HI, the equilibrium concentrations are [H₂] = 0.25 mol/L, [I₂] = 0.3 mol/L, [HI] = 0.5 mol/L. Find the equilibrium constant K_c.

[H₂] = 0.25[I₂] = 0.3[HI] = 0.5

K_c =

3.Medium

0.4 mol/L of H₂ and 0.4 mol/L of I₂ are put in a container and react: H₂ + I₂ ⇌ 2HI, with K_c = 25. Find the equilibrium concentration [HI].

[H₂]₀ = [I₂]₀ = 0.4 mol/LK_c = 25

[HI] = mol/L

4.Medium

1 mol/L of H₂ and 1 mol/L of I₂ are put in a container and react: H₂ + I₂ ⇌ 2HI, with K_c = 9. Find the equilibrium concentration [HI].

[H₂]₀ = [I₂]₀ = 1 mol/LK_c = 9

[HI] = mol/L

5.Hard

PCl₅ decomposes: PCl₅ ⇌ PCl₃ + Cl₂, with K_c = 0.01 at the reaction temperature. A container starts with 0.1 mol/L of PCl₅ only. Find the equilibrium concentration [Cl₂].

[PCl₅]₀ = 0.1 mol/LK_c = 0.01

[Cl₂] = mol/L

6.Hard

PCl₅ decomposes: PCl₅ ⇌ PCl₃ + Cl₂, with K_c = 0.08 at the reaction temperature. A container starts with 0.2 mol/L of PCl₅ only. Find the equilibrium concentration [PCl₅].

[PCl₅]₀ = 0.2 mol/LK_c = 0.08

[PCl₅] = mol/L

Answer key

1. K_c = 0.225
2. K_c = 3.333
3. [HI] = 0.5714 mol/L
4. [HI] = 1.2 mol/L
5. [Cl₂] = 0.02702 mol/L
6. [PCl₅] = 0.1073 mol/L

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