1. i) The pH scale measures how acidic or basic a solution is. The scale goes from 0 to 14.
ii) If pH is less than 7, the substance is acidic. If the pH is 7, the substance is neutral. If pH is more than 7, the substance is basic. Most substances are neutral.
2. pH = -log(5 × 10⁻⁵) ≈ 4.30
3. pH = -log(1) = 0
4. HCl is a strong acid, so [H⁺] = 0.01 M. pH = -log(0.01) = 2.00
5. NaOH is a strong base, so [OH⁻] = 0.05 M. pOH = -log(0.05) ≈ 1.30. pH = 14.00 - 1.30 = 12.70
6. HCl is a strong acid, so [H⁺] = 0.0235 M. pH = -log(0.0235) ≈ 1.63
7. For a 0.0235 M HCl solution, [H⁺] = 0.0235 M. pH ≈ 1.63. pOH = 14.00 - 1.63 = 12.37
8. KOH is a strong base, so [OH⁻] = 6.50 × 10⁻³ M. pOH = -log(6.50 × 10⁻³) ≈ 2.19. pH = 14.00 - 2.19 = 11.81
Parent Tip: Review the logic above to help your child master the concept of acid base ph worksheet.
