Question

When pure ammonium chloride is dissolved in pure water, the $pH$ of the resulting solution is not $7$. This is because:

• A. ammonium ions accept protons from water molecules leaving free $O{H}^{-}$ ions in the solution
• B. ammonium ions donate protons to water molecules forming $H_3{O}^{+}$ ions in the solution
• C. ammonium ions combine with water molecules to give the weak base, ammonium hydroxide
• D. chloride ion make the solution acidic

Answer 1

Answer: (B)

ammonium ions donate protons to water molecules forming $H_3{O}^{+}$ ions in the solution

When pure ammonium chloride is dissolved in pure water, the following reaction occurs:
$N{H}_{4}Cl+H_{2}O\to H_3{O}^{+}+N{H}_3+C{l}^{-}$
Ammonium ions donate protons to water molecules and because of this, $pH$ of solution decreases from $7$.