Acids and Bases - Strong and weak acids and bases

Strong acids and bases are defined by their complete dissociation (ionization) in aqueous solution. For example, $HCl(aq) \rightarrow H^+(aq) + Cl^-(aq)$.

Weak acids and bases only partially dissociate in aqueous solution, establishing an equilibrium where the position of equilibrium lies far to the left. For example, $CH_3COOH(aq) \rightleftharpoons CH_3COO^-(aq) + H^+(aq)$.

Common strong acids include hydrochloric acid ($HCl$), nitric acid ($HNO_3$), and sulfuric acid ($H_2SO_4$).

Common weak acids include ethanoic acid ($CH_3COOH$), carbonic acid ($H_2CO_3$), and phosphoric acid ($H_3PO_4$).

Common strong bases include Group 1 hydroxides like $LiOH$, $NaOH$, and $KOH$.

Common weak bases include ammonia ($NH_3$) and amines like methylamine ($CH_3NH_2$).

Strength vs. Concentration: Strength refers to the degree of dissociation, whereas concentration refers to the number of moles of acid or base dissolved per unit volume ($mol\,dm^{-3}$).

Experimental distinction: Strong acids have higher electrical conductivity, higher rates of reaction (e.g., with metals or carbonates), and lower $pH$ values compared to weak acids of the same concentration.

The conjugate base of a strong acid is a very weak base, while the conjugate base of a weak acid is a relatively stronger base (though often still weak).