What is the exact pH of a solution of at ? (Given for and ). — Ionic Equilibrium Chemistry Question

💡 Solution & Explanation

$NH_4Cl$ is a salt of a strong acid ($HCl$) and a weak base ($NH_4OH$). The pH of its solution is calculated via the formula: $pH = 7 - \frac{1}{2}pK_b - \frac{1}{2}\log C$. Substituting the given values: $pH = 7 - \frac{1}{2}(4.74) - \frac{1}{2}(-1.0) = 7 - 2.37 + 0.5 = 5.13$.