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.

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1.Easy
02468101214acidicneutralbasicpH = ?

Find the pH pH of a 0.001 mol/L solution of Ba(OH)2, a strong base, at 25 °C.

c = 0.001 mol/L
pH =
2.Easy
02468101214acidicneutralbasicpH 5.5

A solution has a pH of 5.5. Find the hydronium ion concentration [H₃O⁺] in mol/L.

pH = 5.5
[H₃O⁺] = mol/L
3.Medium
02468101214acidicneutralbasicpH = ?

Find the pH pH of a 0.05 mol/L solution of benzoic acid (Ka = 6.3 × 10⁻⁵).

c = 0.05 mol/LKa = 6.3 × 10⁻⁵
pH =
4.Medium
02468101214acidicneutralbasicpH = ?

Find the pH pH of a 0.5 mol/L solution of hydrofluoric acid (Ka = 0.00068).

c = 0.5 mol/LKa = 0.00068
pH =
5.Hard
02468101214acidicneutralbasicpH = ?

A buffer contains 0.4 mol/L acetic acid and 0.05 mol/L of its sodium salt. Ka = 1.8 × 10⁻⁵. Find the pH pH of the buffer.

[HA] = 0.4[A⁻] = 0.05Ka = 1.8 × 10⁻⁵
pH =
6.Hard
02468101214acidicneutralbasicpH = ?

A buffer contains 0.2 mol/L acetic acid and 0.1 mol/L of its sodium salt. Ka = 1.8 × 10⁻⁵. Find the pH pH of the buffer.

[HA] = 0.2[A⁻] = 0.1Ka = 1.8 × 10⁻⁵
pH =

Answer key

  1. 1. pH = 11.3
  2. 2. [H₃O⁺] = 3.162 × 10⁻⁶ mol/L
  3. 3. pH = 2.759
  4. 4. pH = 1.742
  5. 5. pH = 3.842
  6. 6. pH = 4.444

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