When an aqueous solution of is added to an aqueous solution of , what happens to the concentration a — Ionic Equilibrium Chemistry Question

💡 Solution & Explanation

$CH_3COOH$ dissociates to give $CH_3COO^-$ and $H_3O^+$. Adding $CH_3COONa$ introduces a high concentration of the common ion $CH_3COO^-$. This shifts the weak acid dissociation equilibrium backward. Consequently, the concentration of $[H_3O^+]$ decreases. Since $pH = -\log[H_3O^+]$, a decrease in $[H_3O^+]$ results in a corresponding increase in pH.