7.2.5—Appreciate that, under standard conditions,

A weak acid or base ionises only partially in water, so the species and its ions coexist at equilibrium. The equilibrium position depends on the acid/base strength and concentration.

Write a reversible equation and use the conjugate pair to track proton transfer. A weak acid does not mean the solution contains no hydronium; it means most solute remains un-ionised.

Ethanoic acid follows CH₃COOH + H₂O ⇌ H₃O⁺ + CH₃COO⁻. Adding water changes concentrations and pH, but the acid remains a weak equilibrium system.

Weak is not the same as dilute. Strength describes degree of ionisation; dilution describes how much solute is present per volume.