1. Compounds in Aqueous Solutions When dissolved in water, ionic and molecular compounds behave differently.

2. Dissociation The separation of ions that occurs when ionic compounds dissolve

3. Precipitation Reactions During some double replacement reactions, insoluble compounds formDuring some double replacement reactions, insoluble compounds form These compounds form solids and will generally sink to the bottom of the solutionThese compounds form solids and will generally sink to the bottom of the solution

4. Solubility Rules 1.Most sodium, potassium & ammonium compounds are soluble 2.Most nitrates, acetates & chlorates are soluble 3.Most chlorides are soluble EXCEPT: silver, mercury (I) & lead chloride 4.Most sulfates are soluble EXCEPT: barium, strontium & lead sulfate 5.Most carbonates, phosphates & silicates are insoluble EXCEPT those combined with #1 6.Most sulfides are insoluble EXCEPT; calcium, strontium, and those combined with #1

5. Complete Ionic Equations Include all ions involved in the reactionInclude all ions involved in the reaction MUST include symbols to show state of ionMUST include symbols to show state of ion (aq) – aqueous (dissolved) (g) – gas (s) – solid (indicates a precipitate)

6. Example of a Complete Ionic Equation Write the complete ionic equation for the reaction between solutions of cadmium nitrate and ammonium sulfide.

7. Net Ionic Equations Include only those ions which react

8. Example of a Net Ionic Equation Write the net ionic equation for the reaction between solutions of cadmium nitrate and ammonium sulfide.

9. Spectator Ions Those ions which DO NOT take part in the chemical reaction and remain in solution.

10. Example of Spectator Ions Write the spectator ions for the reaction between solutions of cadmium nitrate and ammonium sulfide. 2NH 4 + (aq), 2NO 3 - (aq)