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Steps in Solvation

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					               Steps in Solvation

Endothermic-                        Exothermic-
energy                              energy
absorbing                           releasing
              Dissociation




Dissociation of Ionic      Dissociation of
    Compounds           Covalent Compounds
               Electrolytes
• When ionic
  compounds                  battery     bulb
                              +
  dissociate and a
  charge if applied
  to the solutions
                      Na+        +              -


                       Cl-   deionized water + NaCl
    When Electrolytes are Acids
•Examples:

•      HCl(aq) --> H+(aq) + Cl-(aq)
•      HNO3(aq) --> H+(aq) + NO3-(aq)

•Acids like HCl and HNO3 are called MONOPROTIC acids since
every molecule of HCl or HNO3 produces one H+

•Acids like HCl and HNO3 completely dissociate in water
•These acids are are STRONG ACIDS, and hence also strong
electrolytes
         Colligative Properties
Depend only on the number, not on the
identity, of the solute particles in an ideal
solution.

        Boiling point elevation
        Freezing point depression
        Osmotic pressure
   Osmotic Pressure
Osmosis: The flow of
solvent into the solution
through the
semipermeable
membrane.

Osmotic Pressure: The
excess hydrostatic
pressure on the solution
compared to the pure
solvent.
             Precipitation Reactions
2 KI(aq) + Pb(NO3)2(aq) --> PbI2 (s) + 2 KNO3 (aq)
The reaction between the KI and Pb(NO3)2 results in the
formation of PbI2 which has a very low solubility in water
and forms a solid precipitate.

2 KI(aq) + Pb(NO3)2(aq) --> PbI2 (s) + 2 KNO3 (aq)

For compounds insoluble in water, the attraction between
the oppositely charged ions in the solid crystal are too
strong to be overcome by solvent water molecules.

KNO3, being soluble in water, exists in solution as K+ and
NO3- ions.

				
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posted:7/18/2011
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