Which of the following pairs of solutions will form an acidic buffer upon mixing? — Ionic Equilibrium Chemistry Question

💡 Solution & Explanation

An acidic buffer needs a weak acid and its conjugate base. Mixing 100 mL of strong acid (HCl) with 200 mL of salt ($CH_3COONa$) neutralizes half the salt into $CH_3COOH$. The result is a mixture of $CH_3COOH$ and unreacted $CH_3COONa$.