1. Chemical Reaction Predictions

2. A brief review….

3. Types of Chemical Reactions
Single Displacement
Double Displacement
Decomposition
Synthesis
Combustion

4. Single Displacement A +BC  AC + B
One element shoves the other element out!
Ex. Ca + AlCl3  CaCl Al

5. Double Displacement AB + CD  AC + BD Elements switch partners !
Ex. Na3PO4 + BaCl2  Ba3(PO4)2 + NaCl

6. Decomposition
AB  A + B
Breaking chemical compound up, going from BIG to SMALL !
Ex. Au2O3  Au + O2

7. Synthesis A + B  AB Joining! Making new chemical compound !
Mg + N2  Mg3N2

8. Combustion
HYDROCARBON (compound made up of just Cs and Hs) + O2  CO2 + H2O
Chemical reactions involve a compound burning.
Ex. C2H6 + O2  CO2 + H2O

9. Practice Zinc metal combines with hydrochloric acid (HCl).
Sodium sulfide combines with magnesium oxide.
Sodium metal combines with sulfur.
Calcium oxide breaks down.
C4H8 burns
Gandalf combines aluminum metal with sodium hydroxide in solution. What does he produce?]

10. Aqueous Solutions Compounds dissolved into water.
Can contain molecules or ions in a solution.
How do you distinguish between ion or molecule?

11. DISSOCIATION !!
The ability of a compound to breakdown in a solution into individual ions
Ionic Compounds
Break down into cations and anions
Electrical conductors—ions flow through solution
Molecular Compound
Compound remains intact as “molecules,” no breakdown
Generally NOT electrical conductors

12. Dissociation Reactions
NaCl
CaCl2

13. Nonelectrolyte NO dissociation of the compound into anions and cations
Compound remains in its molecular form when dissolved in a solution
No conduction of electricity
Ex. Pure water, molecular compounds, organic compounds

14. Electrolytes
Compound dissolved in a solution that breaks down into cations and anions.
Dissociates into enough ions to conduct electricity.
Strong vs. weak—dependent on the amount of ions in the solution

15. Strong Electrolyte LOTS of ions present in solution
Light bulb burns brightly !
Complete dissociation of the compound into ions
Good electrical conductor
Ex. NaCl, all soluble ionic compounds, very few molecular compounds

16. Weak Electrolyte Compound is at a crossroads
part dissociates into ions—partial ionization
part still exists in the molecular form
Some electrical conduction but poor
Dimly lit light bulb
Ex. Acetic acid, carboxylic acid/amines

17. What is the concentration ([ ]) of a particular ion in solution?
Sometimes [ion] = [compound], but not always
An ion can have only ONE concentration in a solution
May have multiple sources for one ion. What do you do then? (add them up)

18. Example 1:
Hercules has obtained an aqueous solution of M Na2SO4 and M NaCl. What is the concentration (in molarity) of each ion present in the solution? Total ion concentration?
[Na+] = M
[Cl-] = M
[SO4-2] = M
Total ion concentration = M

19. Example 2:
Oral Rehydration Therapy (ORT) is an electrolyte solution containing 3.5 g NaCl, 1.5 g KCl, 2.9 g sodium citrate (Na3C6H5O7) and 20.0 g glucose (C6H12O6) in 1 liter. What is the molarity of each ion/molecule in a solution of ORT?
Hint: sodium citrate is a strong electrolyte, glucose is a nonelectrolyte
[Na+] = M
[K+] = M
[Cl-] = M
[C6H5O7-3] = M

20. Solubility
How much solute dissolves in a solution to produce a saturated solution
Temperature and Pressure dependent
Increase with increasing temperature
Increases with decreasing temperature (ex. Water in lake)
Pressure increases, solubility increases (ex. Soda can)
TEMPERATURE:
Solubility increase with increasing temperature—applies for most substances, good for liquids
Solubility increases with decreasing temperature—applies to gases (talk about how this applies to aquatic life—eutrophic vs. anoxic conditions with oxygen in water supporting organisms)
PRESSURE:
-not a big influence for solids/liquids
-huge influence on gases
-increased solubility of gas when partial pressure increases in area above solution (p. 476)
**Soft Drinks**--gas escapes from soda as pressure decreases and causes solubility to decrease

21. Particles move back and forth from being dissolved to leaving a solution—equilibrium is reached when this movement is balanced.
A point is reached where adding more solute to a solution will prevent the solute from dissolving in the solution.
Dump a lot of salt into a beaker of water. Have a student continue to stir the solution as much as they can…tell them every salt particle has to dissolve.

22. Types of Solutions 1) Saturated
Maximum amount of solute that can be dissolved in a solvent
Certain temperature and pressure
2) Unsaturated
Solution with LESS solute than the maximum solute amount at a certain temperature and pressure
More solute can be added and dissolved in the solution
3) Supersaturated
Contains MORE solute than the maximum solute amount
At saturated point, any more solute added will fall out of solution…cannot be dissolved.
Saturated solutions are at equilibrium—bath tub is filled to the brim with water, any more would cause overflow and any less would decrease the amount.
Think of tea—ask students about what they consider supersaturated/unsaturated/saturated tea.

23. Solubility Diagrams

24. How much sugar is dissolved at 50 degrees Celcius? Salt?

25. Same as with the simple one just have to look at one line for the correct chemical compounds.
NH4Cl—how much is dissolved at 50 degrees Celcius? NaCl?

26. Solubility Rules
How do we determine which compounds will dissolve in water or not?
Based on data, patterns have been observed and helped develop the rules we follow
Look in your reference packet!!!!

27. Which compounds are soluble in water
Which compounds are soluble in water? 1) BaCl2 2) Pb (NO3)2 3) Na2S 4) BaCO3 5) PbS
Soluble
Insoluble

28. Your Turn…….
NaCl
KBr
KNO3
p. 73 of Merrill textbook Teacher’s Ed.

29. Homework
Read pp ,
Problems p. 160 # 25, 29, 31, 53, 57
Read pp. 1-3 of Reaction Type handout and make notes
Finish solubility worksheet

30. AP Question
Snow White conducts a complete combustion of a hydrocarbon with excess oxygen. This combustion produces equimolar quantities of carbon dioxide and water. What is a possible molecular formula for the compound?
A) C2H2
B) C2H6
C) C4H8
D) C6H6 C