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 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
2.Easy
02468101214acidicneutralbasicpH = ?

Find the pH pH of a 0.001 mol/L solution of hydrochloric acid (HCl), a strong acid.

c = 0.001 mol/L
pH =
3.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 =
4.Medium
02468101214acidicneutralbasicpH = ?

Find the pH pH of a 0.1 mol/L solution of formic acid (Ka = 0.00018).

c = 0.1 mol/LKa = 0.00018
pH =
5.Hard
02468101214acidicneutralbasicpH = ?

A buffer contains 0.25 mol/L hydrofluoric acid and 0.1 mol/L of its sodium salt. Ka = 0.00068. Find the pH pH of the buffer.

[HA] = 0.25[A⁻] = 0.1Ka = 0.00068
pH =
6.Hard
02468101214acidicneutralbasicpH = ?

A buffer contains 0.25 mol/L lactic acid and 0.2 mol/L of its sodium salt. Ka = 0.00014. Find the pH pH of the buffer.

[HA] = 0.25[A⁻] = 0.2Ka = 0.00014
pH =

Answer key

  1. 1. [H₃O⁺] = 0.005012 mol/L
  2. 2. pH = 3
  3. 3. pH = 1.742
  4. 4. pH = 2.382
  5. 5. pH = 2.77
  6. 6. pH = 3.757

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