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 4.7

A solution has a pH of 4.7. Find the hydronium ion concentration [H₃O⁺] in mol/L.

pH = 4.7
[H₃O⁺] = mol/L
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 0.25 mol/L solution of acetic acid (Ka = 1.8 × 10⁻⁵).

c = 0.25 mol/LKa = 1.8 × 10⁻⁵
pH =
4.Medium
02468101214acidicneutralbasicpH = ?

Find the pH pH of a 0.05 mol/L solution of acetic acid (Ka = 1.8 × 10⁻⁵).

c = 0.05 mol/LKa = 1.8 × 10⁻⁵
pH =
5.Hard
02468101214acidicneutralbasicpH = ?

A buffer contains 0.1 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] = 0.1[A⁻] = 0.1Ka = 1.8 × 10⁻⁵
pH =
6.Hard
02468101214acidicneutralbasicpH = ?

A buffer contains 0.2 mol/L hydrofluoric acid and 0.05 mol/L of its sodium salt. Ka = 0.00068. Find the pH pH of the buffer.

[HA] = 0.2[A⁻] = 0.05Ka = 0.00068
pH =

Answer key

  1. 1. [H₃O⁺] = 1.995 × 10⁻⁵ mol/L
  2. 2. [H₃O⁺] = 0.005012 mol/L
  3. 3. pH = 2.675
  4. 4. pH = 3.027
  5. 5. pH = 4.745
  6. 6. pH = 2.565

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