Identify the correct order of increasing pH for aqueous solutions of the following four salts: (X) , — Ionic Equilibrium Chemistry Question

💡 Solution & Explanation

(R) $NH_4Cl$ is a SA-WB salt, thus highly acidic ($pH \ll 7$). (X) $HCOONH_4$ is a WA-WB salt; since $K_a(HCOOH) > K_b(NH_3)$, it is slightly acidic ($pH < 7$). (Y) $CH_3COONH_4$ is a WA-WB salt where $K_a \approx K_b$, so $pH \approx 7$. (Z) $CH_3COONa$ is a WA-SB salt, undergoing anionic hydrolysis to make the solution basic ($pH > 7$). Therefore, the order of increasing pH is R < X < Y < Z.