How is the chemical equation for a strong acid dissociated in water different than that for a weak acid?
We write the equation for the dissociation of a weak acid as an equilibrium reaction, while the dissociation of a strong acid goes to completion.
Most weak acids have
For example, acetic acid has
We write the equation for the dissociation of acetic acid with an equilibrium arrow:
CH₃COOH + H₂O ⇌ CH₃COO⁻ + H₃O⁺
Most strong acids have
For example, hydrochloric acid has
We write the equation for the dissociation of HCl with an reaction arrow pointing to the right:
HCl + H₂O → H₃O⁺ + Cl⁻