Aqueous solutions of , , , and of identical concentrations are provided. Which of the following pair — Ionic Equilibrium Chemistry Question

💡 Solution & Explanation

A buffer requires a weak acid and its conjugate base. Mixing $CH_3COOH$ and $CH_3COONa$ directly forms an acidic buffer (Option D). Mixing a strong acid ($HNO_3$) with the salt of a weak acid ($CH_3COONa$) can also form a buffer, provided the strong acid is the limiting reagent (Volume of $HNO_3$ < Volume of $CH_3COONa$), generating $CH_3COOH$ while leaving unreacted $CH_3COONa$ (Option C).