The correct order of increasing in the following aqueous solution is — Ionic Equilibrium Chemistry Question

💡 Solution & Explanation

KCl is a salt of a strong acid and strong base, so it is neutral ($\text{pH} \approx 7$). $\text{NaHCO}_3$ is an amphiprotic salt of a weakly basic nature ($\text{pH} \approx 8.3$). NaCN is the salt of a very weak acid (HCN) and a strong base, so it undergoes extensive anionic hydrolysis, making it strongly basic ($\text{pH} > 10$). Therefore, the order of increasing $[\text{OH}^-]$ (and thus increasing pH) is KCl < $\text{NaHCO}_3$ < NaCN.