1. Aqueous Solutions & Solution Stoichiometry
Basically chapter 4

2. Basic Definitions Solution – homogeneous mixture of 2+ substances
Solvent – dissolving medium, usually present in the greatest quantity
Aqueous solutions – solutions in which water is the solvent
Solutes – other substances in the solution
Electrolyte – substance whose aqueous solution contains ions

3. Strong Electrolytes
Substances that exist in solution completely ionized.
Includes most ionic compounds, strong acids, and strong bases
Acids: H2SO4, HNO3, HClO4, HClO3, HCl, HBr, HI
Only the 1st proton on H2SO4 completely ionizes
Bases: Group 1 hydroxides, hydroxides of calcium, strontium, and barium
Only the 1st OH- of the group 2 hydroxides completely ionizes

4. Weak Electrolytes Non-electrolytes
Substances that exist in solution only partly ionized, such as weak acids and bases.
Examples include acetic acid & ammonia
Non-electrolytes
Substances that do not form ions in solution
Examples include sugars and alcohols

5. Practice
Classify the following as strong, weak or non-electrolytes. Be able to explain your reasoning.
Calcium chloride, CaCl2
Ammonium sulfate, (NH4)2SO4
Hydrocyanic acid, HCN
Glucose, C6H12O6

6. Precipitation Reactions
Precipitate – insoluble solid formed a reaction in solution
Pb(NO3)2(aq) + 2NaBr(aq)  PbBr2(s) + 2NaNO3(aq)
If the aqueous compounds are written as ions, spectator ions can be crossed out and the net ionic reaction can be written
Pb+2 + 2NO3- + 2Na+ + 2Br-  PbBr2(s) + 2Na+ + 2NO3-
Pb+2 + 2Br-  PbBr2(s)

7. Spectator Ions
Spectator ions are ions that do not actually participate in the chemical reaction
They progress from one side of the reaction to the other without undergoing any change

8. Predicting Precipitates
Memorize solubility rules
If a compound is insoluble or slightly soluble, it will be a precipitate
Any compound that is soluble is aqueous

9. Writing Net Ionic Equations
Write all the reactants that are indicated as solids, liquids, or gases.
Re-write the formulas of aqueous compounds as ions.
Predict and write the products.
Balance the mass and charges using coefficients.
Cross out spectator ions.

10. Practice
Write the net ionic equations for each of the lab situations described below. Assume a reaction occurs in all cases.
Aqueous solutions of silver nitrate and sodium phosphate are mixed.
Aqueous copper(II) sulfate is added to solid sodium carbonate
Hydrogen chloride gas is bubbled through an aqueous solution of lead(II) nitrate.

11. Aqueous solutions of silver nitrate and sodium phosphate are mixed.

12. Aqueous copper(II) sulfate is added to solid sodium carbonate

13. Hydrogen chloride gas is bubbled through an aqueous solution of lead(II) nitrate.