Question

1. Write the equation for the acid ionization of the Zn(H₂O)₆²⁺ ion

2. For each of the following salts, indicate whether the aqueous solution of each of the following salts will be acidic, basic or neutral.

a) Fe(NO₃)₃

b) Na₂CO₃

c) Ca(CN)₂

d) NH₄ClO₄

3. Note whether hydrolysis occurs for each of the following ions, if it does occur write the equation.

a) NO₃^-

b) OCL^-

c) NH₂NH₃⁺

d) Br^-

Answer 1

1.

[Zn(H2O)6]2+ (aq.) + 2 H2O (l) ------------> ZnO (s) + 2 H3O+ (aq.) + 5 H2O (l)

2.

(a)

Fe(NO3)3 (aq.) + 3 H2O (l) ------------> Fe(OH)3 (aq.) + 3 HNO3 (aq.)

Since the given, acid is strong and base is weak, the resulting solution is acidic.

(b)

Na2CO3 is the salt obtained by weak acid (H2CO3) and strong base (NaOH). Hence the resulting solution of Na2CO3 is basic.

(c)

Ca(CN)2 is the salt obtained by weak acid (HCN) and strong base (Ca(OH)2). Hence the resulting solution of Ca(CN)2 is basic.

(d)

NH4ClO4 is the salt obtained by weak base (NH4OH) and strong acid (HClO4). Hence the resulting solution of NH4ClO4 is acidic.

3.

(a) NO₃^- does not undergo hydrolysis

(b) OCl^- (aq.) + H₂O (l) -------------> HOCl (aq.) + OH^- (aq.)

(c) NH₂NH₃⁺ (aq.) + H₂O (l) --------------> NH₂NH₃OH (aq.) + H₊ (aq.)

(d) Br^- does nto undergo hydrolysis