3.1 Proton transfer reactions

• Acid = proton donor

• Base = proton acceptor

• Deduce acid and base in a reaction; distinguish base and alkali

• Differ by one proton

• Deduce conjugate acid/base formulas

• Can act as both acid and base

• Write equations showing acid and base behaviour

• pH = −log₁₀[H⁺]

• [H⁺] = 10⁻ᵖᴴ

• Calculate pH and [H+]; include universal indicator and pH probe use

• Kw = [H⁺][OH⁻]

• Acidic: [H⁺] > [OH⁻]

• Neutral: [H⁺] = [OH⁻]

• Basic: [H⁺] < [OH⁻]

• Recognize acidic, neutral, and basic solutions from [H+] and [OH-]

• Differ in extent of ionization

• Equilibrium favors weaker conjugate

• Distinguish strong/weak from concentrated/dilute

• Acid + metal oxide/hydroxide/carbonate/hydrogencarbonate

• Formulate equations and identify parent acids/bases of salts

• Strong acid-strong base titrations

• Characteristic shapes

• Sketch and interpret intercept and equivalence point for monoprotic titrations

• pOH = −log₁₀[OH⁻]

• [OH⁻] = 10⁻ᵖᴼᴴ

• pH + pOH = 14 (at 25°C)

• Interconvert [H+], [OH-], pH, and pOH

• Ka, Kb, pKa, pKb

• Interpret relative acid/base strength from Ka, Kb, pKa, and pKb

• Ka × Kb = Kw

• Solve problems involving Ka, Kb, and Kw

• pH depends on parent acid/base strength

• Write ion hydrolysis equations and predict salt solution pH

• Four combinations: strong-strong, strong-weak, weak-strong, weak-weak

• Interpret buffer region and points where pH = pKa or pOH = pKb

• Weak acids with colored conjugate pairs

• Color change at pH ≈ pKa

• Write indicator equilibria and include universal indicator as a mixture

• End point coincides with equivalence point

• Choose indicators from salt identity and indicator pH range; distinguish end point and equivalence point

• Resist pH change

• Acidic buffers: weak acid + conjugate base

• Basic buffers: weak base + conjugate acid

• Explain buffer action using weak acid/base conjugate systems

• Buffer pH depends on pKa/pKb and acid/base to conjugate ratio

• Solve buffer composition and pH problems using equilibrium constants

• Explain the effect of dilution on buffer pH