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Essential Knowledge AP Chemistry
Week 1 and 2
Before we even start the assigned AP Chemistry curriculum you
MUST know how to name compounds. We went through most of
this last year but it needs to become a second hand notion quickly.
YOU MUST MEMORIZE THE POLYATOMIC IONS ON PAGE
2! TEST FRIDAY 9/12. START TODAY!
Objective: Identify, name, and write the formulas for
A) Covalent Compounds
B) Monatomic Ion, Binary Ionic Compounds
C) Polyatomic Ionic Compounds
D) Acids and Bases
Schedule: Week 1 (09/02-09/05)
- Tuesday 09/02/14: Student presented with essential knowledge packet
- Wednesday 09/03/14: Review of covalent and monatomic ionic bonds
- Thursday 09/04/14: Naming and writing Polyatomic Ions
- Friday 09/05/14: Naming and writing acids and bases
Schedule: Week 2 (09/08-09/12)
- Monday 09/08/14: Review; Poster
- Tuesday 09/09/14: Review Poster
- Wednesday 09/10/14: Test 1 on naming covalent bonds and naming
ionic bond; naming polyatomic ions, and acids/bases
- You will be given polyatomic ion sheet seen on page 2
- Thursday: Syllabus, introduction to Chapter 1 of Zumdahl
- Friday 09/12/14: Test on naming polyatomic ions (memorize page 2)
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Poly = More than one or multiple, ion = charged particle
Name
ammonium
Symbol
NH4+
acetate
C2H3O2-
Bromate
BrO3-
Perchlorate
ClO4-
Chlorate
ClO3-
Chlorite
ClO2-
Hypochlorite
ClO-
Cyanide
CN-
Dihydrogen phosphate
H2PO4-
Hydrogen carbonate (bicarbonate)
HCO3-
Hydrogen sulfate (bisulfate)
HSO4-
Hydrogen sulfite (bisulfite)
HSO3-
Hydroxide
OH-
Iodate
IO3-
Nitrate
NO3-
Nitrite
NO2-
Permanganate
MnO4-
Thiocyanate
SCN-
Carbonate
CO32-
Dichromate
Cr2O72-
Chromate
CrO42-
Oxalate
C2O42-
Selenate
SeO42-
Silicate
SiO32-
Sulfate
SO42-
Sulfite
SO32-
Peroxide
O22-
Phosphate
PO43-
Phosphite
PO33-
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A) Covalent Compounds
A1: What is a covalent compound?
A covalent compound is a compound in which the atoms that are bonded share electrons
rather than transfer electrons from one to the other. While ionic compounds are usually formed
when metals or a metal and a metalloid bond to nonmetals, covalent compounds are formed
when two nonmetals bond to each other.
Rules in naming Covalent Compounds
A2: Common Covalent Compound
Some common covalent compounds have common names. These compounds do not
follow the rules found below. We will be discussing many of these but there are some
you should know that I have listed below.
Compound
H2O
CH4
NH3
O3
Name
Water
Methane
Ammonia
Ozone
A3: Diatomic Covalent Compounds
Diatomic molecules (dia meaning two) are molecules that bind together. They are
common and not found alone in nature. Since these molecules NEVER are alone so
their name is their name on the periodic table. They include all gasses other than the
Nobel gasses.
Compound
H2
N2
O2
F2
Cl2
I2
Br2
Name
Hydrogen
Nitrogen
Oxygen
Fluorine
Chlorine
Iodine
Bromine
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A4: Naming Rest of Binary (2 total) Covalent Compounds
The rest of the covalent compounds require prefixes as seen below. You need to
memorize these prefixes if you already don’t know them. Prefixes are necessary when
naming covalent compounds because the atoms can combine in any whole number
ratio. N2O, for example, cannot simply be called “nitrogen oxide,” because there are
several other compounds that contain nitrogen and oxygen. We must specify that there
are two nitrogen atoms bonded to a single oxygen atom.
Rules
1. The first element is named first, using the elements
name.
2. Second element is named as an Anion (suffix "-ide")
3. Prefixes are used to denote the number of atoms
4. "Mono" is not used to name the first element
Note: when the addition of the Greek prefix places two
vowels adjacent to one another, the "a" (or the "o") at
the end of the Greek prefix is usually dropped; e.g.,
"nonaoxide" would be written as "nonoxide", and
"monooxide" would be written as "monoxide". The "i"
at the end of the prefixes "di-" and "tri-" are never
dropped.
Prefix
monoditritetrapentahexaheptaoctanonadeca-
You also need to know which element to put
first in the formulas and names of these
compounds. Generally, they are in the same
left-to-right order that they have on the
periodic table, except that you would have to
squeeze hydrogen in between nitrogen and
oxygen.
Examples:
Compound
Name
NO*
N2O
NO2*
N2O3
N2O4
N2O5
Nitrogen Monoxide
Dinitrogen Monoxide
Nitrogen Dioxide
Dinitrogen Trioxide
Dinitrogen Tetraoxide
Dinitrogen Pentaoxide
* Notice that the prefix “mono” is omitted in these cases
number
indicated
1
2
3
4
5
6
7
8
9
10
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A: Covalent Compound Practice
Write the formulas for the following covalent compounds:
1) antimony tribromide __________________________________
2) hexaboron silicide __________________________________
3) chlorine dioxide __________________________________
4) hydrogen iodide __________________________________
5) methane __________________________________
6) oxygen __________________________________
7) iodine pentafluoride __________________________________
8) bromine __________________________________
9) dinitrogen trioxide __________________________________
10) ammonia __________________________________
11) phosphorus triiodide __________________________________
12) nitrogen __________________________________
13) water __________________________________
14) ozone __________________________________
15) dinitrogen monoxide __________________________________
Write the names for the following covalent compounds:
16) P4S5__________________________________
17) O2 __________________________________
18) SeF6 __________________________________
19) Si2Br6 __________________________________
20) SCl4 __________________________________
21) CH4 __________________________________
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22) B2Si __________________________________
23) NF3 __________________________________
24) O3 __________________________________
25) Cl2 __________________________________
26) NH3 __________________________________
27) H2 __________________________________
28) CO __________________________________
29) CO2 __________________________________
30) NO2 __________________________________
Name of Covalent Compound
Formula of Covalent Compound
carbon dioxide
phosphorus triiodide
sulfur dichloride
nitrogen trifluoride
dioxygen difluoride
N2F4
SCl4
ClF3
SiO2
P4O10
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B) Monatomic ions, Diatomic ionic compounds
B1: What is an ionic compound?
An ionic compound is a compound in which transfer from one atom to the other.
Ionic compounds are usually formed when metals bond to nonmetals. After this transfer of
electrons, the atom that loses electrons becomes positively charged and is referred to as a cation
and the atom that gains the electrons becomes negatively charged and is referred to as an anion.
B2: Naming Monatomic Ions
In order to determine the charge of monatomic ions, you can use the periodic table as a guide:
Group #
Ion Charge
Examples
(Column)
1
These elements lose one electron to form +1 ions.
Na+, Li+, K+
2
These elements lose two electrons to form +2 ions.
Mg2+, Ca2+, Ba2+
The elements in groups 3-12 are called transition
metals. These elements always lose electrons to
form positive ions (cations) but their charges vary.
Fe2+, Fe3+
Groups 312
For example, iron can form a +2 or a +3 ion. In cases
like these, you must be told which ion to use.
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These elements lose three electrons to form +3 ion.
Al3+
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The charges on these ions vary. Carbon and silicon
do not form ions. For the rest of the group, you must
be given the charge.
Sn2+, Pb2+
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These elements gain three electrons and form –3
ions.
N3-, P3-
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These elements gain two electrons to form –2 ions.
O2-, S2-
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These elements gain one electron to form –1 ions.
F-, Cl-, Br-, I-
These atoms do NOT form ions. Their charge is
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He, Ne, Ar, Kr
always zero.
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Naming Ions (Nomenclature):
Simple cations are named by saying the element and adding the word “ion.”
Na+ is called “sodium ion”
Mg2+ is called “magnesium ion”
Simple anions are named by dropping the ending off the element name and adding “ide.”
F- is called “fluoride”
O2- is called “oxide”
N3- is called “nitride”
Note: the charge of a monatomic anion is equal to the group number minus 18
B2 Practice: name the following ions
1) F  ________________________________
2) Ca2+ ________________________________
3) Pb4+________________________________
4) I ________________________________
5) Al3+________________________________
6) Cd2+________________________________
7) Fe3+________________________________
Write the formula for each of the following ions:
8) sulfide ion ________________________________
9) thallium (III) ion ________________________________
10) sodium ion ________________________________
11) cobalt (II) ion ________________________________
12) barium ion ________________________________
13) bromide ion ________________________________
14) iodide ion _______________________________
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B3: Naming Binary Ionic Compounds
Ionic compounds are compounds formed by the combination of a cation and a anion. (Think:
“metal plus nonmetal”). Ionic compounds are more commonly known as “salts.” Binary
ionic compounds are compounds containing only two elements, as demonstrated in the
examples below.
When writing formulas for ionic compounds, we use subscripts to indicate how many of each
atom is contained in the compound. Remember that even though ions have charges, ionic
compounds must be neutral. Therefore, the charges on the cation and the anion must cancel
each other out. In other words, the net charge of an ionic compound equals zero.
Example 1:
For a salt containing sodium ion, Na+, and chloride, Cl-, the ratio is one to one. The positive
charge on the sodium ion cancels out the negative charge on the chloride.
(+1) + (-1) = 0
Therefore, the formula for the salt is NaCl. (The actual formula is Na1Cl1, but chemists omit
subscripts of 1).
Example 2:
For a salt containing calcium ion, Ca2+, and chloride, Cl-, the ratio can’t be one to one.
(+2) + (-1) = +1
Remember that ionic compounds must be neutral. In order to yield a neutral compound, two
chlorides must bond to the calcium ion:
(+2) + 2(-1) = 0
So, the formula for this salt is CaCl2.
Nomenclature:
When naming ionic compounds, simply write the element name of the metal followed by the ion
name of the nonmetal. (Remember: the metal ion (cation) is always written first!)
NaCl is called “sodium chloride,” and CaCl2 is called “calcium chloride.”
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B3 Practice: Name the following binary compounds
Name of Ionic Compound
Formula of Ionic Compound
1. Sodium bromide
2. Calcium chloride
3. Magnesium sulfide
4. Aluminum oxide
5. Lithium phosphide
6. Cesium nitride
7. Potassium iodide
8. Barium fluoride
9. Rubidium nitride
10. Barium oxide
11.
K2O
12.
MgI2
13.
AlCl3
14.
CaBr2
15.
Na3N
16.
LiF
17.
Ba3P2
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B4: Ionic Compounds Containing Transition Metals
The transition metals are the elements located in the middle of the periodic table (in groups 312. Unlike the group 1A and 2A metal ions, the charges of transition metal ions are not easily
determined by their location on the periodic table. Many of them have more than one charge
(also known as an oxidation state). There are eight transition metals that you should highlight
on your periodic table:
Co, Cr, Cu, Fe, Mn, Hg, Sn, and Pb
Each of these elements form more than one ion and therefore must be labeled accordingly. For
example, iron forms two ions: Fe2+ and Fe3+. We call these ions “iron (II) ion” and “iron (III)
ion” respectively. (See “Table of Transition Metal Ions”).
When naming any ion from the elements listed above, you MUST include a Roman numeral in
parentheses following the name of the ion. The this roman numeral is equal to the charge on
the ion. We don’t include the “+” because all metal ions are positive. Here are two more
examples:
Pb4+ = “lead (IV) ion”
Cr3+ = “chromium (III) ion
Similarly, when naming a compound containing one of these transition metals, you must
include the Roman numeral as well. “Iron Chloride” isn’t specific enough since the compound
could contain either iron (II) or iron (III) ion. You must specify the charge on the iron.
Iron (II) chloride contains the Fe2+ ion. When combined with chloride, Cl-, we know the
formula must be FeCl2.
Iron (III) chloride contains the Fe3+ ion. This time, three chlorides are required to form a neutral
compound. Therefore, the formula is FeCl3.
By looking at the formula of an ionic compound, we can determine the charge (oxidation
state) of the metal.
Example: Write the name of Co2O3
1. Recognize that Co, cobalt, is a transition metal. This means that you must include a Roman
numeral after its name. So, the basic name will be Cobalt (__) Oxide.
2. To find the charge on cobalt, use oxide as a key. Oxide has a charge of –2 so three oxides
will have a charge of –6.
3. What balances a –6 charge? A +6 charge! So, the positive half of the compound must
equal +6.
4. Since there are two cobalt ions, the charge is split between them. So, each one has a +3
charge. Therefore, we are using the Co3+ ion and the compound is called cobalt (III)
oxide.
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Remember that anions (negative ions) always have a definite charge. When dealing with
compounds containing transition metals, look to the anion first. Determine the charge of the
anion and then solve to figure out the charge of the cation.
When dealing with metals other than the transition metals, you don’t need Roman numerals. In
other words, calcium ion, Ca2+ is always +2. Don’t call CaCl2 “calcium (II) chloride.” Its name
is “calcium chloride.”
B4 Practice: Naming Binary Ionic Compounds
Name of Ionic Compound
Formula of Ionic Compound
1. Copper (II) sulfate
2. Copper (I) oxide
3. Chromium (III) cyanide
4. Cobalt (II) hydroxide
5. Silver bromide
6. Zinc nitrate
7. Iron (III) acetate
8. Lead (IV) sulfate
9.
FeCl2
10.
PbSO3
11.
Co2(CO3)3
12.
AgNO3
13.
Zn(CN)2
14.
CuClO3
15.
Cr(OH)3
16.
Hg2O
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C) Polyatomic Ionic Compounds
C1: What is a Polyatomic Ions
Polyatomic ions contain two or more different atoms (polyatomic means “many atoms”). Here
are some common examples:
THIS WILL HELP YOU MEMORIZE THE POLYATOMIC IONS!
a. ammonium ion, NH4+ (the only positive polyatomic ion you need to know)
b. “ATE” ions: contain an atom bonded to several oxygen atoms:
Nitrate = NO3-
Phosphate = PO43-
Sulfate = SO42-
Carbonate = CO32-
Acetate = CH3CO2-
Chlorate = ClO3-
c. “ITE” ions: remove one oxygen from the “ATE” ion and keep the same charge:
Nitrite = NO2-
Phosphite = PO33-
Sulfite = SO32-
Chlorite = ClO2d. Other common complex ions:
Hydroxide = OH-
Cyanide = CN-
C2: How to name Ionic Compounds Containing Polyatomic Ions
As you’ve already learned, ionic compounds are formed by the combination of a positive ion
(cation) and a negative ion (anion). This is the same when dealing simple ions or complex ions.
Be careful to note, however, that complex ions are grouped together and should not be
separated. In other words, don’t ever separate the sulfate ion, SO42- into sulfur and oxygen. If it’s
written as a group, keep it as a group!
Since complex ions come in groups, things can get tricky when using subscripts. As a result,
we use parentheses to separate the ion from the subscript:
If we need two sulfates in a compound, we write: (SO4)2.
If we need three nitrates in a compound, we write: (NO3)3.
And, just as before, the net charge of the compound must be zero. For a salt containing sodium
ion, Na+, and nitrate, NO3-, the ratio would be 1:1 since the positive and negative charges cancel
out. Therefore, the formula is NaNO3 and is called sodium nitrate. (Note: no parentheses are
necessary here).
For a salt containing calcium ion, Ca2+, and nitrate, NO3-, the ratio must be 1:2 (one
calcium ion for every two nitrates). So, the formula would be Ca(NO3)2.
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C2 Practice: How to name Ionic Compounds Containing Polyatomic Ions
Name of Ionic Compound
Formula of Ionic Compound
1. Sodium chromate
2. Calcium carbonate
3. Magnesium nitrate
4. Aluminum sulfate
5. Lithium phosphate
6. Ammonium chloride
7. Cesium chlorate
8. Potassium sulfate
9. Barium acetate
10. Rubidium cyanide
11.
KCH3CO2
12.
Mg3(PO4)2
13.
Al(ClO3)3
14.
CaSO4
15.
Sr(HCO3)2
16.
NaNO3
17.
Li2CO3
18.
Ba(NO3)2
19.
Cs2CrO4
20.
NH4OH
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D) Acids and bases
D1: What is an acid and a base?
Acids and bases are ionic compounds with one difference.
Acids always have hydrogen as the cation and some other anion
Bases always have OH-1 as the anion with some metal as the cation:
D2: Naming Acids
To start, acids and bases are named the SAME WAY we learned how to name ionic
compounds because they are ionic compounds
However there is more to naming acids and bases as seen below
ACIDS: Oxyacids = oxygen containing, Non-oxyacds = non oxygen containing
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D3: Naming Bases
Naming bases is much easier. In a sense it is the SAME way we name polyatomic ions
where the ANION is hydroxide.
D2 and D3 Practice: Naming acids and Bases
Write the formula for these acids
1. Nitric acid
2. Chloric acid
3. Acetic acid
4. Nitrous acid
5. Hydrofluoric acid
Write the name of these acids
6. HNO2
7. HI (aq)
8. HC2H3O2
9. H2CO3
10. H2SO3
Fill in the blank for these acids and bases
19. NaOH
20.
Magnesium hydroxide
21.
Ammonium hydroxide
22. Ca(OH)2
Great Practice!
Write the formulas for the following:
a. Barium sulfate ________________
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a. CuSO4 _____________________
b. Ammonium chloride _____________
b. PCl3 _______________________
c. Chlorine monoxide _____________
c. Li3N _______________________
d. Silicon tetrachloride ____________
d. BaSO3 _____________________
e. Magnesium fluoride ____________
e. N2F4 _______________________
f. Sodium oxide ________________
f. KClO4 _______________________
g. Sodium peroxide _____________
g. NaH ________________________
h. Copper (i) oxide _____________
h. (NH4)2Cr2O7 ___________________
i. Zinc sulfide _________________
i. HNO2 * _______________________
j. Potassium carbonate ___________
j. Sr3P2 ________________________
k. Hydrobromic acid ____________
k. Mg(OH)2 _____________________
l. Perchloric Acid ______________
l. Al2S3 ________________________
m. Lead (ii) acetate _____________
m. AgBr ________________________
n. Sodium permanganate ____________
n. P4O10 _______________________
o. Lithium oxalate _______________
o. HC2H3O2 * ___________________
p. Potassium cyanide ______________
p. CaI2 _________________________
q. Iron (iii) hydroxide ______________
q. MnO2 _______________________
r. Silicon dioxide _________________
r. Li2O _________________________
s. Nitrogen trifluoride _____________
s. FeI3 _________________________
t. Chromium (iii) oxide _____________
t. Cu3PO4 ______________________
u. Calcium chlorate ________________
u. PCl5 _________________________
v. Sodium thiocyanate ______________
v. NaCN _______________________
w. Nitrous acid ____________________
w. HF * ________________________
* - Name as acids
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