1. Semester Two Final Review 2016
Chemistry

2. Stoichiometry – Balanced Equations
A balanced chemical equation tells the ratio of the number of moles of one compound to moles of another compound
Another example…
2 CoBr3 + 3 CaSO4  3 CaBr2 + 1 Co2(SO4)3
3 moles of CaSO4 used to 1 mole of Co2(SO4)3 produced
How many moles Co2(SO4)3 of can be produced if we start with 12 moles of CoBr3 and an excess of CaSO4?

3. Stoichiometry – The Box Method
Use the box with grams!
Moles is on the bottom in this box
Balance the equation first if needed!
Molar mass: add masses from the periodic table
Down = divide; up = multiply
The ONLY way to move between compounds is from moles to moles

4. Acids and Bases – The Box Method
Use the box with liters!
Moles is on the TOP in this box
Down = divide; up = multiply
The ONLY way to move between compounds is from moles to moles

5. Stoichiometry – The Box Method
Write chemical formulas: + and - charges MUST CANCEL
Oxide and hydroxide are NOT the same thing
Balance the equation
Use the box

6. Solutions Concentration and molarity (M) mean the same thing
How much solute is dissolved in a solvent
Most concentrated = highest molarity
Least concentrated = lowest molarity

7. Solutions – Freezing Point
Dissociation factor: how many particles a solute will break into in water
Ionic (metal + nonmetal) = breaks apart
Circle any polyatomic ions – the group stays together!
Covalent (nonmetals) = stays together = df of 1
Freezing point calculations use molality (mol divided by kg)

8. Solutions – Solubility Graph
Solubility is temperature dependent
Saturated = contains the maximum amount of solute at that temperature
Any point on the curve
Precipitate = solid that forms
#26-29 in packet

9. Acids and Bases – pH Calculations
Use the flow chart!
Acidic, basic, or neutral?
Always find the pH to tell
pH less than 7 = acidic
pH greater than 7 = basic

10. Acids and Bases – Neutralization Reactions
Double replacement reactions
One product is ALWAYS water (H2O)
CIRCLE polyatomic ions – they stay together
Formulas: + and – charges must cancel

12. Now try problem #12 in your pink review packet!
Solutions Example #1
What is the molarity of a solution in which g of silver nitrate is dissolved in mL of solution?
Now try problem #12 in your pink review packet!

13. Now try problem #12 in your pink review packet!
Solutions Example #1
What is the molarity of a solution in which g of silver nitrate is dissolved in mL of solution?
Now try problem #12 in your pink review packet!

14. Now try problem #24 in your pink review packet!
Solutions Example #2
What is the boiling point of a solution of 48.3 g of LiCl in 450 g of water?
Now try problem #24 in your pink review packet!

15. Now try problem #28 in your pink review packet!
Solutions Example #3
A saturated solution of sodium nitrate is cooled from 60oC to 20oC. How many grams of precipitate form?
Now try problem #28 in your pink review packet!

16. Acids and Bases Example #1
Anion Ending
Acid Name
-ide
hydro-(stem)-ic acid
-ite
(stem)-ous acid
-ate
(stem)-ic acid
Name the following and determine whether the compound is an acid, a base, or neither one.
a. HCl
b. Be(OH)2
Now try problem #33 in your pink review packet!

17. Acids and Bases Example #2
Write the formulas of the following compounds.
a. Nitrous acid
b. Magnesium hydroxide
c. Chloric acid
Anion Ending
Acid Name
-ide
hydro-(stem)-ic acid
-ite
(stem)-ous acid
-ate
(stem)-ic acid
Now try problem #34 in your pink review packet!

18. Acids and Bases Example #3
Calculate the pH of a solution in which the [OH-] = 3.6 x Is the solution acidic, basic, or neutral?
Now try problem #39a in your pink review packet!

19. Acids and Bases Example #4
Calculate the [H+] of a solution in which the pOH = 7.2.
Now try problem #40a in your pink review packet!

20. Acids and Bases Example #5
Write the complete balanced neutralization reaction for the reaction of phosphoric acid and barium hydroxide.
Now try problems #43-44 in your pink review packet!

21. Acids and Bases Example #6
A 45 mL solution of H2SO4 is completely neutralized by 22 mL of 1.25 M NaOH. What is the molarity of the H2SO4 solution?
Moles (mol)
Molarity (M)
Liters (L)
Now try problem #45 in your pink review packet!

22. Acids and Bases Example #7
What is the molarity of H2SO4 if 55 mL is neutralized by 1.5 M NaOH according to the curve below?
Moles (mol)
Molarity (M)
Liters (L)
Now try problem #47 in your pink review packet!

23. Acids and Bases Practice
A 60 mL solution of HCl is completely neutralized by 22 mL of 0.50 M Ba(OH)2. What is the molarity of the HCl solution?
Moles (mol)
Molarity (M)
Liters (L)
Now try problem #45 in your pink review packet!