AP CHEMISTRY- REVIEW
Review1
UNCERTAINTIES REVIEW

As part of your Lab Group. Analyze the following
data.





Mass of beaker:
7.15 g +/- 0.01 g
Mass of beaker + metal: 12.12g +/- 0.01 g
Height of cube:
2.12 cm +/- 0.01 cm
Width of cube:
1.05 cm +/- 0.01 cm
Length of cube:
0.75 cm +/- 0.01 cm
Calculate the density of the cube with uncertainty.
 Given the theoretical density as 2.65 g/cm3 Find the
% error and Discuss which type of error is more
significant.

CONVERSIONS

A mole of anything is equal to 6.02 x1023
1 mole of an element is equal to its molar mass.
So 1 mole of Carbon = 12g of C= 6.02x1023 atoms of C

Convert 875 grams of C to atoms of carbon?

Convert 3.156x1022 atoms of C to grams of C?


MOLAR MASS







Molar mass is the mass of one mole of an element or
compound.
If its an element we can find the molar mass by looking at
the atomic mass of that element. Example, N-14 g
If it’s a compound we must calculate it by multiplying the
number of atoms times each atomic mass.
Example. Find the molar mass of Ca3(PO4)2
3 (Ca) + 2(P) + 8 (O)
3 (40) + 2 (31) + 8 (16)
120 + 62 + 128 = 310 g
COVALENT COMPOUNDS




Covalent compounds exist as molecules. They are made up
of nonmetals atoms.
Water: H2O is made up of atoms of hydrogen and oxygen,
both nonmetals. So it’s a covalent compound and exists as
molecules.
1 mole of water = 6.02 x1023 molecules and each molecule
contains 3 atoms. Two of hydrogen and one of oxygen.
Calculate the number of molecules in 45 grams of C2H6
COVALENT NOMENCLATURE


In naming covalent compounds , you must use prefixes to
identify the number of each atom in the formula. You never
reduce. First element keep its name, second ends in ide.
Prefixes:

1= mono
6= hexa

The prefix mono is not usually used for the first element.

Carbon Dioxide= CO2

Dichlorine tetraoxide = ?

2= di
3= tri
4= tetra 5= penta
7= hepta 8= octa 9= nona 10= deca
Disulfur Dichloride= S2Cl2
IONIC COMPOUNDS





These are compounds formed when metal atoms combined
with nonmetal atoms or polyatomic ions.
What are polyatomic ions?
1 mole of an ionic compound is equal to 6.02 x1023 Formula
units. ( fu’s)
Sodium Chloride- NaCl- is an ionic compound and one mole
of sodium chloride is equal to 6.02 x10 23 fu. Each fu is
made up of two atoms, one of Na and one of Cl.
Calculate how many atoms are found in 285 grams of CaCl2
POLYATOMIC IONS





Nitrate
Acetate
Carbonate
Ammonium
Cyanide
NO3-1
C2H3O2-1
CO3-2
NH4+1
CN-1
Phosphate
Sulfate
Chlorate
Hydroxide
Peroxide

- ite ending = one oxygen less than ate
Hypo---ite= one oxygen less than ite
Per-----ate= one oxygen more than ate

What’s the formula for:




Hypochlorite
Persulfate
PO4-3
SO4-2
ClO3-1
OH-1
O2-1
IONIC FORMULAS

Find the charges of each ion, cross them and reduce if
possible
Aluminum Nitride Al+3
N-3
Al3N3 AlN

Sodium Phosphate






Na+1
PO4-3
Na3PO4
Some metals like Copper have more than one charge, thus
we use Roman numbers to identify them
Copper I = Cu+1
Copper II= Cu+2
Lead II, Lead IV
Iron II, Iron III
Tin II, IV
Many of the transitional metals have multiple charges. The
ones above, you MUST know.
Zinc is always +2, Silver is always +1
ASSIGNMENT

1. Convert the following: Show set up





A) 1.15 grams of gold to atoms
B) 2.85 grams of Aluminum oxide to atoms
C) 0.88 grams of Carbon Dioxide to molecules
D) 2.805 x1018 molecules of water to grams
E) How many formula units of Calcium Sulfite in 888 grams.
2. Write the formulas for the following compounds
A) Copper I acetate
F) Disilicon trioxide
B) Zinc Sulfide
G) Lead IV Chromate
C) Dinitrogen hexaoxide
H) Magnesium peroxide
D) Iron III Perphosphate
I) Calcium Hypochlorite
E) Silver nitrate
J) Sulfur Dioxide