1. AP Chemistry Chapters 1-3 Review

2. Identify complete and balance reactions
Synthesis-
Two elements combining to form a compound. Remember ionic compounds you must check charges. You should know elements that are diatomic.
Example: Aluminum metal reacts with oxygen gas
Decomposition
A compound is heated and breaks down into two or more products. Know how Carbonates and chlorates beake up.
Example:
Copper I Carbonate is heated
Potassium Chlorate is heated

3. Identify complete and balance reactions
Single Replacement
Nonmetal by itself replaces nonmetal in a compound.
Example
Fluorine gas reacts with sodium oxide
Metal by itself replaces metal in acompound.
Example:
Potassium reacts with aluminum oxide

4. Identify complete and balance reactions
Double Replacement
Ionic compounds exchanging ions.
Example:
Aluminum Nitrate reacts with Potassium carbonate
Combustion
CxHy + Oxygen gas produces carbon dioxide and water
C5H12 reacts with oxygen gas

5. Polyatomic Ions You should know the following:
Nitrate Chlorate Hydroxide All -1 charge
Carbonate Sulfate All -2 charge
Phosphate All -3 charge
All –ite are one oxygen less than –ate
Per-ate are one oxygen more than ate.
Example:
Perchlorate and Sulfite

6. Limiting and Excess
You should be able to solve Limiting –Excess problem such as the one below:
75 grams of Calcium oxide reacts with 125 grams of Aluminum solid
Write the complete and balanced reaction
Identify the Limiting reagent with calculations
Calculate the theoretical mass of Aluminum oxide
Calculate the actual yield in the lab if your percent yield was 82.5%

7. Empirical and Molecular Formulas
Find the Empirical and molecular formula of a compound given the following data
1. C= 59.0%, H= 7.1%, O=26.2%, N= 7.7%. The molecular weight of compound is 360 amu
2. A compound with the formula of CxHyOz, when you react 2.00 grams with excess oxygen gas, you produce grams of carbon dioxide and 1.00 grams of steam. Given this information calculate the compound’s empirical formula. If the molecular weight of compound is216 amu, calculate its molecular formula.

8. Hydrate Formula A compound has the following formula MgSO3 XH2O
Mass of hydrate 4.00 grams
Mass after heating 2.37 grams
Calculate the value of X in the hydrate

9. Protons- Neutrons- Electrons
Symbol
At. Mass
At. #
Protons
Neutrons
Electrons
Charge 12 17 +2
42K+1 67 30 31

10. Significant Figures Calculate the following:
A) (25500 X 0.100) /(100X250)=
B) ( )/ 0.150=
Calculate the density given the following:
Mass of beaker + metal
25.55 g +/- 0.02
Mass of beaker
15.15 g +/- 0.02
Volume of water
10.0 +/- 0.1 mL
Volume of water + metal
12.5 +/- 0.1 mL
Theoretical Density of metal
4.0 g/mL
Calculate Mass of metal with % uncertainties. C) Calculate Density with Uncertainties
Calculate Volume with % uncertainties D) calculate % error, Random error and Systematic error

11. Average Mass
Given that you have three isotopes of element X, whose average mass is
Find the % abundance of the isotope of X with a mass of 415, given; that you have three isotopes 414 is 2.5% the other two are 415 and 416

12. Mass-Moles- Molecules- Atoms
Solve the following:
1.50 moles of water to grams
85.6 grams of CO2 to molecules
1.25 grams of HC2H3O2 to atoms of hydrogen
6.15 x1025 formula units of NaF tomass.