1. Net Ionic Equations

2. Interesting Fact: The BENDS Deep sea divers may experience a condition called the "bends" if they do not readjust slowly to the lower pressure at the surface. As a result of breathing compressed air and being subjected to high pressures caused by water depth, the amount of nitrogen dissolved in blood and other tissues increases.

3. If the diver returns to the surface too rapidly, the nitrogen forms bubbles in the blood as it becomes less soluble due to a decrease in pressure. The nitrogen bubbles can cause great pain and possibly death

4. Net Ionic Equations In aqueous solutions, ionic compounds dissociate into their ions. E.g. Sr(NO 3 ) 2(aq) → Sr 2+ (aq) + 2NO 3 - (aq) Total ionic equations show all dissociated ions of soluble ionic compounds. Spectator ions are ions that remain in solution and therefore are not involved in a chemical reaction. Net ionic equations show only ions involved in a chemical reaction (I.e. spectator ions are NOT included)

5. An Example The reaction between aqueous sodium chloride & silver nitrate. Chemical Equation: NaCl (aq) + AgNO 3(aq)  NaNO 3(aq) + AgCl (s) Total Ionic Equation: Na + (aq) + Cl - (aq) + Ag + (aq) + NO 3 - (aq)  Na + (aq) + NO 3 - (aq) + AgCl (s) Net ionic Equation: Ag + (aq) + Cl - (aq)  AgCl (s)

6. Remember the Solubility Table? You need to use the solubility table to predict if there is going to be a precipitate.

7. Another Example The reaction between aqueous sodium chloride & magnesium nitrate. Chemical Equation: 2 NaCl (aq) + Mg(NO 3 ) 2(aq)  2 NaNO 3(aq) + MgCl 2(aq) Total Ionic Equation: 2Na + (aq) + 2Cl - (aq) + Mg 2+ (aq) + 2NO 3 - (aq)  2Na + (aq) + 2NO 3 - (aq) + Mg 2+ (aq) + 2Cl - (aq) Net ionic Equation: No reaction!

8. Write the total ionic eq'n and the net ionic eq'n for the reaction that occurs when lead (II) nitrate and potassium iodide combine.

9. Write the net ionic equation for aluminum metal being placed in a solution of copper (II) chloride.

10. Identifying Ions Today we can use a mass spectrometer to determine the ions present. Various techniques were used in the past. These techniques are still used today for qualitative analysis. o Review Table 9.1 and 9.2 on page 411-412. These tables show the colour of common ions in solutions and the colour produced by an ion in a flame test. o Read pg 411-412 & complete Activity 9.2 on pg.413.

11. Practice p. 414 #5a, 10, 12, 14a