Question

Write balanced molecular equations for the following potential precipitation reactions. Indicate the states of reactants and products [(aq) or (s)].

(b) In those cases where a precipitate forms, write the net ionic equation. If there is no reaction, state "No reaction."

(i) (NH4)2SO4 (aq) + Cr(NO3)3 (aq) →

(ii) K2SO4 (aq) + AgNO3 (aq) →

(iii) Cr(CH3CO2)3 (aq) + KOH (aq) →

(iv) Mg(ClO3)2 (aq) + K3PO4 (aq) →

Each of the following salts can be prepared from an acid and a base. Write the balanced molecular equation and the net ionic equation for the preparation of each. Indicate states of the reactants and products [(aq), (s), (l)]. Review solubility rules if necessary to determine the solubility of the reactants.

(a) LiCH3CO2 (aq)

(b) Pb(NO3)2 (aq)

(c) BaCl2 (aq)

Answer 1

(i) 3(NH4)2SO4 (aq) + 2Cr(NO3)3 (aq) → Cr2(SO4)3(s) + 6NH4NO3(aq) molecular equation

6(NH4)^+(aq) + 3SO4^2- (aq) + 2Cr^3+(aq) + 6(NO3)^- (aq) → Cr2(SO4)3(s) + 6NH4^+(aq) + 6NO3^-(aq)

Removal spectator ions to get net ionic equation

2Cr^3+(aq) +3SO4^2- (aq) → Cr2(SO4)3(s)    net ionic equation

(ii) K2SO4 (aq) + 2AgNO3 (aq) → Ag2SO4(s) + 2KNO3(aq) molecular equation

       2K^+(aq) + SO4^2- (aq) + 2Ag^+(aq) + 2NO3^- (aq) → Ag2SO4(s) + 2K^+(aq) + 2NO3^-(aq)

Removal spectator ions to get net ionic equation

2Ag^+(aq) + SO4^2- (aq) + → Ag2SO4(s)   net ionic equation

(iii) Cr(CH3CO2)3 (aq) + 3KOH (aq) → Cr(OH)3(s) + 3CH3COOK(aq)

Cr^3+(aq) + 3(CH3CO2)^- (aq) + 3K^+(aq) + 3OH^- (aq) → Cr(OH)3(s) + 3CH3COO^-(aq) + 3K^+(aq)

Removal spectator ions to get net ionic equation

Cr^3+(aq) + 3OH^- (aq) → Cr(OH)3(s)    net ionic equation

(iv) 3Mg(ClO3)2 (aq) + 2K3PO4 (aq) →Mg3(PO4)2(s) + 6KClO3(aq)

3Mg^2+(aq) + 6(ClO3)^- (aq) + 6K^+(aq) + 2PO4^3- (aq) →Mg3(PO4)2(s) + 6K^+(aq) + 6ClO3^-(aq)

Removal spectator ions to get net ionic equation

3Mg^2+(aq) + 2PO4^3- (aq) →Mg3(PO4)2(s)    net ionic equation

b.

a)    LiOH(aq) + CH3COOH(aq) ------------> LiCH3CO2 (aq) + H2O(l)

      Li^+(aq) + OH^-(aq) + CH3COO^-(aq) +H^+(aq) ------------> Li^+(aq) + CH3CO2^- (aq) + H2O(l)

Removal spectator ions to get net ionic equation

H^+(aq) + OH^- (aq) -------------> H2O(l) net ionic equation

(b) Pb(OH)2(aq) + 2HNO3(aq) -------------> Pb(NO3)2 (aq) + 2H2O(l)

     Pb^+2(aq) + 2(OH)^-(aq) + 2H^+(aq) + 2NO3^-(aq) -------------> Pb^2+ (aq) + 2(NO3)^- (aq) + 2H2O(l)

Removal spectator ions to get net ionic equation

H^+(aq) + OH^- (aq) -------------> H2O(l) net ionic equation

   

(c) Ba(OH)2(aq) + 2HCl(aq) ------------>BaCl2 (aq) + 2H2O(l)

Ba^2+(aq) + 2(OH)^-(aq) + 2H^+(aq) + 2Cl^-(aq) ------------>Ba^2+ (aq) + 2Cl^- (aq) + 2H2O(l)

Removal spectator ions to get net ionic equation

H^+(aq) + OH^- (aq) -------------> H2O(l) net ionic equation