AP Chemistry
Name _________________________
Period ___ Date ___/___/___
1-3  Foundations of Chemistry
Notes
Naming & Writing Compounds
Ions
Cations: Positive ions formed by the loss of electrons
Anions: Negative ions formed by gaining electrons
Naming Ionic Compounds
Positive ion is always named first, negative ion second
Find the "ate" ion (sulfate, for instance) sulfate =
The "ite" ion always has one less oxygen
4 than the "ate" ion sulfite =
The prefix "per" (think hyper, meaning "above")
is used with the "ate" prefix to indicate
3
one more oxygen than the "ate" ion
The prefix "hypo" (meaning "under" or "below") is used with the "ite" prefix to indicate
one less oxygen than the "ite" ion
Examples (Just because you can name it doesn't mean it exists!)
Perchlorate ClO4
Pernitrate
Chlorate
Chlorite
4
ClO3
-
Nitrate
3
ClO2
-
Nitrite
2
hypochlorite
ClO-
hyponitrite
NO NO NO NO-
Metals with more than one oxidation state (transition metals) must have a roman
numeral to indicate the oxidation state
Fe3+ = iron (III)
Mn+2 = manganese (II)
Practice:
1. sodium oxide
______________
2. magnesium iodide
______________
3. lithium chloride
______________
4. beryllium bromide
______________
5. aluminum sulfide
______________
6. calcium bromide
______________
7. beryllium oxide
______________
8.
9.
10.
11.
12.
____________________________
____________________________
____________________________
____________________________
____________________________
Al(ClO)3
Ba(NO3)2
KHSO4
Cu2SO3
Pb(C2O4)2
Naming Covalent Compounds
1. Must contain two elements, BOTH nonmetals
a. First element
full element name
prefix only if there is more than one atom
b. Second element
named as if it were an anion (-ide suffix)
always gets a prefix
mono - 1
penta - 5
octa - 8
di - 2
hexa - 6
nona - 9
tri - 3
hepta - 7
deca - 10
tetra - 4
Practice
13. N2O3
________________________________________________________
14. CO2
________________________________________________________
15. CO
________________________________________________________
16. NO3
________________________________________________________
17. NO2
________________________________________________________
18. carbon tetrabromide
___________________
19. nitrogen triiodide
___________________
20. phosphorous pentafluoride
___________________
21. silicon dioxide
___________________
22. sulfur hexachloride
___________________
Naming Acids
Binary Acids (two elements - hydrogen + one other)
prefix "Hydro" + root of second element + "ic" suffix
Oxyacids
c. If the acid contains an anion whose name ends in "ate":
Use root of anion name and an "ic" ending (H2SO4 = sulfuric acid)
d. If the acid contains an anion whose name ends in "ite": Use the
root of the anion name and an "ous" ending (H2SO3 = sulfurous
acid)
Practice
23. HCl
___________________________________
24. H2SO4
___________________________________
25. HNO3
___________________________________
26. H3PO4
___________________________________
27. HClO3
___________________________________
Significant Figures and Calculations
A. Rules for Counting Significant Figures
Number
Rule
Nonzero integers Always significant
Leading zeroes
Never significant
Captive zeroes
Always significant
Trailing zeroes
Significant if after a decimal
Exact numbers
Infinite significance
Scientific notation
All digits are significant
Example
6.34 m (3 sig figs)
0.00634 m ( 3 sig figs)
6.0034 (5 sig figs)
63400 (3 sig figs)
0.63400 (5 sig figs)
e.g. There is 1 star at the
center of our solar system.
There is no doubt about
the number "1"
6.3400 x 106 (5 sig figs)
B. Multiplication and Division
Keep as many sig figs in your answer as are in the piece of data with the least
number of sig figs
2.37 cm x 15.67 cm x 7.4 cm = 274.82046
(keep two sig figs) = 2.7 x 102 cm3
C. Addition and Subtraction
Keep the same number of decimal places as the least precise measurement
in your calculation
34.039 m + 0.24 m + 1.332 m + 12.7 m = 48.311 m
(keep one decimal place) = 48.3 m
D. Rules for Rounding
Round at the end of a series of calculations, NOT after each step
Use only the first number to the right of the last sig fig to decide whether or
not to round
a. Less than 5, the last significant digit is unchanged
b. 5 or more, the last significant digit is increased by 1
Practice
28. 1.03338000
29. 0.00003300
30. 133,555,800
31. 5.000001
32. 58.5g + 34g =
33. 3358g ÷ 7mL =
34. 85.889g ÷ 28cm3 =
Dimensional Analysis
Full credit can never be given for working a problem in which you do not do all of the following:
1. Observe significant figures rules
2. Label all steps of your work with the correct units
3. Correctly label and identify your answer
4. Solve the problem in a manner that can be understood by the reader.
Practice
35. If a penny weighs 2.50 grams, what would be the volume of 1 penny (density of a penny is 8.933 g/
mL)
36. What will be the volume in liters of 16.0 grams of oxygen if 1 mL of oxygen weighs 0.00143 grams?
37. The density of sodium hydroxide solution is 1.1589 g/mL. What is the mass of 550 mL of this
solution?
38. How large a container, in milliliters, would you need to hold 7.2 kg of gasoline? (the density of
gasoline is 0.68 g/mL)
39. Light travels at a speed of 3.00 X 1010 cm/s. What is that speed in km/hr?
Stoichiometry
The Mole
Avogadro's number
6.022 x 1023 units = 1 mole
Named in honor of Avogadro (he did NOT discover it)
Measuring moles
An element's atomic mass expressed in grams contains 1 mole of atoms of that
element
12.01 grams of carbon is 1 mole of carbon
12 grams of carbon-12 is 1 mole of carbon-12
A. Molar Mass (Gram molecular weight)
The mass in grams of one mole of a compound
The sum of the masses of the component atoms in a compound
EX: Molar mass of ethane (C2H6):
Percent Composition of Compounds
Calculating any percentage
"The part, divided by the whole, multiplied by 100"
Percentage Composition
Calculate the percent of each element in the total mass of the compound
(#atoms of the element)(atomic mass of element) x 100 (molar mass of the
compound
Practice
40. What is the percent iron in iron (III) oxide?
Determining the Formula of a Compound
Determining the empirical formula
Determine the percentage of each element in your compound
Treat % as grams, and convert grams of each element to moles of each element
Find the smallest whole number ratio of atoms
If the ratio is not all whole number, multiply each by an integer so that all elements
are in whole number ratio
Determining the molecular formula
Find the empirical formula mass
Divide the known molecular mass by the empirical formula mass, deriving a
whole number, n
Multiply the empirical formula by n to derive the molecular formula
Practice:
41. What is the empirical formula of a compound contains 0.0130 mol carbon, 0.0390 mol
hydrogen, and 0.0065 mol oxygen.
42. What is the empirical formula of a compound consists of 72.2% magnesium and 27.8% nitrogen
by mass.
43. What is the molecular formula of a compound has an empirical formula of NO2 and a molar
mass of 92.02 g/mol.
Stoichiometric Calculations: Amounts of Reactants and Products
Balance the chemical equation
Convert grams of reactant or product to moles
Compare moles of the known to moles of the desired substance
A ratio derived from the coefficients in the balanced equation
Convert from moles back to grams if required
Calculations Involving a Limiting Reactant
Concept of limiting reactant (limiting reagent):
" I want to make chocolate chip cookies. I look around my kitchen (I have a BIG kitchen!) and find 40
lbs. of butter, two lbs. of salt, 1 gallon of vanilla extract, 80 lbs. of chocolate chips, 200 lbs. of flour,
150 lbs. of sugar, 150 lbs. of brown sugar, ten lbs. of baking soda and TWO eggs. It should be clear
that it is the number of eggs that will determine the number of cookies that I can make."
The limiting reactant controls the amount of product that can form
Solving limiting reactant problems
Convert grams of reactants to moles
Use stoichiometric ratios to determine the limiting reactant
Solve as before, beginning the stoichiometric calculation with the grams of the
limiting reactant
Percent Yield
Actual yield - what you got by actually performing the reaction
Theoretical yield - what stoichiometric calculation says the reaction SHOULD have
produced
Actual Yield
Yield
x 100%
= percent yield Theoretical
44. What is the maximum number of grams of PH3 that can be formed when 6.2 g of
phosphorus reacts with 6.0 g of hydrogen to form PH3?
45. Copper is formed when aluminum reacts with cupric sulfate in a singlereplacement reaction. How many grams of copper can be obtained when 29.0 g
of Al reacts with 156 g or cupric sulfate?