1. Topic: Reactions in Aqueous Solution Do Now: Label the following at (aq) or (s) 1. NaBr 2. PbNO 3 3. KOH 4. CuSO 4 5. Ba 2 S

2. Formation of a precipitate 2 aqueous solutions mixing to produce a new compound that is insoluble (a solid)

3. Demo KI + PbNO 3  KNO 3 + PbI AgNO 3 + NaCl  AgCl + NaNO 3

4. Reactions in aqueous solution Many reactions, esp. many double replacement reactions, occur in water. What happens when substances dissolve in water? Depends on if they are ionic or covalent.

5. Dissolving an Ionic Substance in water  it splits into the ions that make up the compound Example: NaCl(s)  Na + (aq) + Cl - (aq) CaCl 2 (s)  Ca 2+ (aq) + 2Cl - (aq) AlCl 3 (s)  Al 3+ (aq) + 3Cl - (aq) The ions are spread out among the water molecules.

6. Lets check to see if there are really ions Conductivity = conduct electricity – Need charged particles (ions) to travel

7. Electrolytes = compounds that conduct electricity Ionic compounds that dissolve in water are electrolytes

8. Dissolving a Covalent Substance in water  split into individual molecules NOT IONS Ex: sucrose C 12 H 22 O 11 (s)  C 12 H 22 O 11 (aq) The sugar molecules are spread out among the water molecules.