pH & buffers worksheet with answers

Free printable pH & buffers 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
02468101214acidicneutralbasicpH = ?

Find the pH pH of a 0.02 mol/L solution of Ba(OH)2, a strong base, at 25 °C.

c = 0.02 mol/L
pH =
2.Easy
02468101214acidicneutralbasicpH 2.3

A solution has a pH of 2.3. Find the hydronium ion concentration [H₃O⁺] in mol/L.

pH = 2.3
[H₃O⁺] = mol/L
3.Medium
02468101214acidicneutralbasicpH = ?

Find the pH pH of a 0.1 mol/L solution of benzoic acid (Ka = 6.3 × 10⁻⁵).

c = 0.1 mol/LKa = 6.3 × 10⁻⁵
pH =
4.Medium
02468101214acidicneutralbasicpH = ?

Find the pH pH of a 0.2 mol/L solution of hypochlorous acid (Ka = 3 × 10⁻⁸).

c = 0.2 mol/LKa = 3 × 10⁻⁸
pH =
5.Hard
02468101214acidicneutralbasicpH = ?

A 1.00 L buffer contains 0.25 mol hypochlorous acid and 0.15 mol of its conjugate base (Ka = 3 × 10⁻⁸). 0.05 mol of NaOH is added. Find the new pH pH.

n(HA) = 0.25 moln(A⁻) = 0.15 moln(OH⁻) = 0.05 molKa = 3 × 10⁻⁸
pH =
6.Hard
02468101214acidicneutralbasicpH = ?

A 1.00 L buffer contains 0.25 mol benzoic acid and 0.15 mol of its conjugate base (Ka = 6.3 × 10⁻⁵). 0.01 mol of NaOH is added. Find the new pH pH.

n(HA) = 0.25 moln(A⁻) = 0.15 moln(OH⁻) = 0.01 molKa = 6.3 × 10⁻⁵
pH =

Answer key

  1. 1. pH = 12.6
  2. 2. [H₃O⁺] = 0.005012 mol/L
  3. 3. pH = 2.606
  4. 4. pH = 4.111
  5. 5. pH = 7.523
  6. 6. pH = 4.025

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