1. 1.15 Using Solubility Rules to Predict Precipitate Formation pp. 54 - 60

2. Chemical Reactions in Solution A solution is a homogeneous mixture in which a solute – substance in lesser quantity – is dissolved in a solvent – substance in greater quantity. An aqueous solution is a solution in which water is the solvent. – The subscript (aq) denotes an aqueous solution A solid that is formed as a result of the chemical reaction of two aqueous solutions is called a precipitate.

3. Solubililty Solubility is a measure of the amount of a substance that dissolves in water at a given temperature and pressure. A substance with low solubility will remain solid when mixed with water or precipitate out of the solution. – This is denoted with a subscript (s) for solid. Table 1 on p. 54 tells us which ionic compounds are soluble and which has low solubility.

4. Practice ___ AgNO 3(aq) + ___ CaCl 2(aq)  ___ NaOH (aq) + ___ Ca(NO 3 ) 2(aq)  If both products are soluble, there is no reaction – write NR after the arrow NaNO3 (aq) + KCl (aq) 

5. Total & Net Ionic Equations A total ionic equation depicts the separation of soluble ionic compounds into their respective ions – Re-write an each aqueous ionic compound as two ions. If not aqueous just re-write the chemical. – e.g. Na 2 SO 4(aq) = 2Na + (aq) + SO 4 2- (aq) – e.g. CaSO 4(s) = CaSO 4(s) Write the total ionic equation for the following reaction: – Na 2 SO 4(aq) + CaCl 2(aq)  CaSO 4(s) + 2NaCl (aq)

6. Total & Net Ionic Equations 2Na + (aq) + SO 4 2- (aq) + Ca 2+ (aq) + 2Cl - (aq)  CaSO 4(s) + 2Na + (aq) + 2Cl - (aq) If an ion exists on both sides of an equation it means it does not participate in the reaction and so it is called a spectator ion. A net ionic equation depicts only the ions that are involved in a chemical reaction. – Cross out the spectator ions in the total ionic equation and re-write what’s left.

7. Net Ionic Equation Write the net ionic equation for the above reaction: 2Na + (aq) + SO 4 2- (aq) + Ca 2+ (aq) + 2Cl - (aq)  CaSO 4(s) + 2Na + (aq) + 2Cl - (aq) After crossing out the spectator ions we are left with: SO 4 2- (aq) + Ca 2+ (aq)  CaSO 4(s)