Ionic Equilibrium

Three main theories define acids

Three main theories define acids and bases: (1) Arrhenius Theory: Acids produce H⁺ ions, bases produce OH⁻ ions in water. (2) Brønsted-Lowry Theory: A

For weak acid HA

For weak acid HA: Ka = [H₃O⁺][A⁻]/[HA]. For weak base BOH: Kb = [B⁺][OH⁻]/[BOH]. These constants measure the strength of weak acids and bases. Higher

Water undergoes auto

Water undergoes auto-ionization: 2H₂O ⇌ H₃O⁺ + OH⁻. Kw = [H₃O⁺][OH⁻] = 1.0 × 10⁻¹⁴ at 25°C. pH = -log[H₃O⁺], pOH = -log[OH⁻], pH + pOH = 14. Neutral s

When a common ion is added

When a common ion is added to a solution of a weak electrolyte, the equilibrium shifts according to Le Chatelier's principle, suppressing ionization.

Solutions that resist pH changes upon

Solutions that resist pH changes upon addition of small amounts of acid or base. Two types: (1) Weak acid + its salt (acidic buffer), (2) Weak base +