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Soluble Salts



                                                                                         What is solubility?

       (a) to separate a salt from a mixture of salts

       (b) to prepare a salt sample





       (c) to identify cations and anions through qualitative analysis






                                                                                              Soluble Salts

        (a) all nitrates and ethanoates

        (b) all sodium, potassium and ammonium salts

        (c) all chlorides except silver chloride (AgCl), lead (II) chloride (PbCl2), and mercury chloride (HgCl2)

             * Lead (II) chloride dissolves in hot water but not in cold water

          (d) all sulphate except barium sulphate (BaSO4), lead (II) sulphate (PbSO4), and calcium sulphate (CaSO4)

          (e) lead halides that is lead (II) chloride (PbCl2), lead (II) iodide (PbI2), lead (II) bromide (PbBr2), only dissolve in hot










                                                                         Preparation of soluble salts

        (a) Reaction between acid and alkali/base called neutralization/titration:


        (b) Reaction between acid and base oxide:


        (c) Reaction between acid and reactive metal:


        (d) Reaction between acid and metal carbonate:







                                                                                 Methods of preparing soluble salts

1. Soluble salts of sodium, potassium and ammonium salts



        KOH (aq) + HNO3 (aq)                KNO3 (aq) + H2O (l)

        NaOH (aq) + HCl (aq)                 NaCl(aq) + H2O (l)

        2NH3 (aq) + H2SO4 (aq)             (NH4)2SO4 (aq)

        2NaOH (aq) + H2SO4 (aq)            Na2SO4 (aq) + H2O (l) 


2. Soluble salts that is exclude of sodium, potassium and ammonium salts



         (a) Zn (s)    +    H2SO4 (aq)            ZnSO4 (aq)    +    H2 (g)

              (metal   +    acid            salt    +    hydrogen)

         (b) Zn0 (s)    +    H2SO4 (aq)            ZnSO4 (aq)    +    H2O(l)

              (oxide metal   +    acid            salt    +    water)

         (c) Zn(OH)2 (s)    +    H2SO4 (aq)            ZnSO4 (aq)    +    2H2O(l)

              (hydroxide metal   +    acid             salt    +    water)

         (d) ZnCO3 (s)    +    H2SO4 (aq)              ZnSO4 (aq)    +    H2O(l)    +    CO2 (g) 

              (carbonate metal   +    acid            salt    +    water    +    carbon dioxide)