Match each aqueous salt solution on the left to the corresponding hydrolyzing ion or hydro… — JAMB UTME

Match each aqueous salt solution on the left to the corresponding hydrolyzing ion or hydrolysis behavior on the right.

Ammonium chloride solution, $NH_4Cl(aq)$ $NH_4^+$ undergoes cation hydrolysis to produce $H_3O^+$ ions
Sodium sulfide solution, $Na_2S(aq)$ $S^{2-}$ undergoes anion hydrolysis to produce $OH^-$ ions
Iron(III) nitrate solution, $Fe(NO_3)_3(aq)$ $[Fe(H_2O)_6]^{3+}$ undergoes hydrolysis to produce $H_3O^+$ ions
Potassium sulfate solution, $K_2SO_4(aq)$ Neither cation nor anion undergoes hydrolysis

Ammonium chloride matches with

NH_4^+

cation hydrolysis producing

H_3O^+

; Sodium sulfide matches with

S^{2-}

anion hydrolysis producing

OH^-

; Iron(III) nitrate matches with

[Fe(H_2O)_6]^{3+}

hydrolysis producing

H_3O^+

; Potassium sulfate matches with neither ion undergoing hydrolysis.

Matching each salt depends on identifying which ion hydrolyzes. Ammonium chloride contains the weak acid cation

NH_4^+

which yields hydronium ions; sodium sulfide contains the weak acid conjugate base

S^{2-}

which generates hydroxide ions; iron(III) nitrate contains the hydrated cation

[Fe(H_2O)_6]^{3+}

which donates a proton to water; and potassium sulfate consists only of non-hydrolyzing spectator ions.

Identify the parent acid and base for each salt to determine which ions undergo hydrolysis.

Salts derived from weak parents hydrolyze:

NH_4^+

comes from weak base

NH_3

S^{2-}

comes from weak acid

H_2S

[Fe(H_2O)_6]^{3+}

is a weak acidic complex ion, whereas

K^+

and

SO_4^{2-}

come from strong parent species.

Only ions derived from weak acids or weak bases are strong enough conjugate species to react significantly with water.

Write the hydrolysis equilibrium equations for the reactive species.

NH_4^+ + H_2O \rightleftharpoons NH_3 + H_3O^+

S^{2-} + H_2O \rightleftharpoons HS^- + OH^-

, and

[Fe(H_2O)_6]^{3+} + H_2O \rightleftharpoons [Fe(H_2O)_5(OH)]^{2+} + H_3O^+

Cation hydrolysis increases the concentration of hydronium ions (

H_3O^+

), while anion hydrolysis increases the concentration of hydroxide ions (

OH^-

Pair each salt solution with its correct hydrolyzing species and resulting ionic effect.

Each salt is uniquely matched to its hydrolysis behavior.

Matches strictly conform to Brønsted-Lowry acid-base and salt hydrolysis principles.

Salt Hydrolysis and Solution Acidity/Alkalinity

Question