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Chemical Bonds
•Bonds between atoms are created when electrons
are paired up by being transferred or shared.
•Atoms tend to form bonds that will allow it to obtain
a full valence shell.
Two Types of Chemical Bonds:
Ionic Bonds
Covalent Bonds
-Electrons are transferred
from one atom to another
-Electrons are shared
between atoms.
- Usually occurs between a
metal and nonmetal
- Usually occurs between two
nonmetals
Compounds
Compounds are formed when two or more
kinds of atoms are bound together
chemically. Compound can be either ionic
or covalent.
Examples:
Why do these bonds occur?
Remember: In a neutral atom the number of protons and
neutrons are equal but the atom might be unhappy because it
does not have a complete outer shell of electrons(8 electrons).
All atoms want to be happy like the Nobel gases!!!!!
How can atoms be happy?
-By creating either an ionic or covalent bond.
-If they create an ionic bond they either gain or lose an
electron.
-Positive ion form by losing an electron
-Negative ion form by gaining an electron
Groups turning Ionic...
Positive Ions (cation)
Group 1
Loses 1 electron
Ion with a +1
Charge
Group 2
Loses 2 electrons
Ion with a +2
Charge
Group 13
Loses 3 electrons
Ion with a +3
Charge
Negative Ions (anion)
Group 15
Gains 3 electrons
Ion with a -3
charge
Group 16
Gains 2 electrons
Ion with a -2
charge
Group 17
Gains 1 electron
Ions with a -1
charge
Naming Binary Covalent Compounds
Prefix
number indicated
monoditritetrapentahexaheptaoctanona-
1
2
3
4
5
6
7
8
9
deca-
10
Examples
:
Formula
Names
N2F6
Dinitrogen Hexafluoride
CO2
SiF4
CBr4
NCl3
P2S3
CO
NO2
SF2
PF5
SO2
NO
CCl4
P2O5
Naming Binary Ionic Compounds
Rules
1. The Cation (positive ion) is named first, the Anion second.
2. Monoatomic Cations take the element name
Na+ --> Sodium
Ca2+ --> Calcium
3. Monoatomic Anions take the elements name and ends with "-ide"
Cl- --> Chloride
NaCl --> Sodium Chloride
Li3N --> Lithium Nitride
Note** Greek prefixes are not used to indicate the number of atoms
of each element in the formula unit for the compound
(e.g., Na2O is named "sodium oxide" not "disodium oxide", or
"disodium monoxide").
Examples
:
Formula
Name
Formula
a. Li2O
Lithium Oxide
n. K2O
b. CsCl
o. RbI
c. MgS
p. Mg3N2
d. CaBr2
q. Ca3P2
e. BaI2
r. Al2S3
f. KH
s. Ag2O
g. Na2S
t. NaH
h. AlN
u. CaO
i. AgF
v. Na2S
j. ZnO
w. LiI
k. CdI2
x. CdS
l. BaS
y. ZnCl2
m. LiCl
z. CsI
Name
Naming Ionic Compounds using Roman
Numerals
(The Stock System of Naming)
How do we name compounds when the cation of variable charge is
involved?
•Some elements have more then one oxidation number
and when naming a compound these must be identified.
•Roman numerals are shown after the cation in
parenthesis( ) to indicate the oxidation number.
•To determine what the oxidation number is, you must use
the anion (negative ion) to determine what the positive
oxidation number is.
Example- Pb(NO3)4 write the name "lead nitrate".
Since lead has more than one oxidation state we must figure out which lead we have.
Since each nitrate (4 of them) has a 1- charge, the Pb must be 4+. So our roman numeral will be (IV).
Pb(NO3)4 is named "lead(IV) nitrate"
Formula
Name
Formula
FeCl2
iron (II) chloride
SnCl4
CoBr3
FeP
MnO2
Hg2S
NiBr2
PbO
HgO
AuI
CuF2
SnS2
CuI
FeBr3
SnBr2
Cr2O3
Au3P
CoS
Cr2S3
MnI2
NiBr
NiS
FeS
PbO2
PbCl4
Mn2O5
Name
II. Nonbinary Ionic compounds
(Use of Polyatomic Ions)
Nonbinary means more than two different elements
Step 1
Step 2
First give the name of the metal, followed by the memorized polyatomic ion
name.
If the metal is to the right of group IIA, then a
Roman numeral is used after the metal to describe the charge of the metal. Except
Ag, Zn, and Al.
Examples
NaOH
Fe(SO4)2
Fe(NO3)3
Zn(C2H3O2)2
Memorized Polyatomic Ion List
Formula
Name
Formula
Name
NH4+
C2H3O2CO32-
Ammonium
Acetate
Carbonate
O22NO3NO2-
Peroxide
Nitrate
Nitrite
HCO31-
SO42-
Sulfate
ClO4-
Hydorgen
carbonate
Perchlorate
SO32-
Sulfite
ClO3ClO2ClOCNOH-
Chlorate
Chlorite
Hypochlorite
Cyanide
Hydroxide
PO43PO33CrO42Cr2O72MnO41-
Phosphate
Phosphite
Chromate
Dichromate
Permanganate
II. Nonbinary Ionic compounds
Nonbinary means more than two different elements
Step 1
First give the name of the metal, followed by the memorized polyatomic ion
name.
Step 2
CO
If the metal is to the right of group IIA, then a
Roman numeral is used after the metal to describe the charge of the metal. Except
Ag, Zn, and Al.
Examples
NaOH
Fe(SO4)2
Sodium hydroxide
Fe(NO3)3
Zn(C2H3O2)2
II. Nonbinary Ionic compounds
Nonbinary means more than two different elements
Step 1
First give the name of the metal, followed by the memorized polyatomic ion
name.
Step 2
If the metal is to the right of group IIA, then a
Roman numeral is used after the metal to describe the charge of the metal. Except
Ag, Zn, and Al.
Examples
NaOH
Fe(SO4)2
Sodium hydroxide
Fe(NO3)3
Zn(C2H3O2)2
Iron(III) nitrate
II. Nonbinary Ionic compounds
Nonbinary means more than two different elements
Step 1
First give the name of the metal, followed by the memorized polyatomic ion
name.
Step 2
If the metal is to the right of group IIA, then a
Roman numeral is used after the metal to describe the charge of the metal. Except
Ag, Zn, and Al.
Examples
NaOH
Fe(SO4)2
Sodium hydroxide
Iron(II) sulfate
Fe(NO3)3
Zn(C2H3O2)2
Iron(III) nitrate
II. Nonbinary Ionic compounds
Nonbinary means more than two different elements
Step 1
First give the name of the metal, followed by the memorized polyatomic ion
name.
Step 2
If the metal is to the right of group IIA, then a
Roman numeral is used after the metal to describe the charge of the metal. Except
Ag, Zn, and Al.
Examples
NaOH
Fe(SO4)2
Sodium hydroxide
Iron(II) sulfate
Fe(NO3)3
Zn(C2H3O2)2
Iron(III) nitrate
Zinc acetate
NOMENCLATURE
COVALENT BONDS
(non-metal with nonmetal)
IONIC BONDS
(metal with non-metal)
POLYATOMIC ION
(more than 2 elements in
the compound)
Rules:
• Use pre-fixes
(mono-, di-, tri-,
tetra-, penta-, etc…)
• Second element ends
with the suffix “-ide)
Rules:
• No pre-fixes!
• Second element ends
with the suffix “-ide)
Rules:
• Find polyatomic ion
on the cheat sheet.
• If the polyatomic ion
is listed first, then the
second element ends
with the suffix “-ide)
• If the polyatomic ion
is listed last, then
simply name the first
element.
If there is a TRANSITION
METAL (groups 3-12)
present, then use roman
numerals (I, II, III, IV, V)
Balancing Chemical Equations
Recall:
•The law of Conservation of Matter (mass). Matter can not be created or
destroyed only changed.
•A chemical equation is a way to show matter being changed from one
compound to another.
For example:
H + O ------> H O
•This equations show when hydrogen and oxygen combine it makes
water. But look closer.... In the first half of the equation you have one
hydrogen and one oxygen and in the second you have two hydrogen
and one oxygen. You must balance this equation due to the law of
conservation of matter. With the equation the way it is, you are saying
that you created another hydrogen and you can not create matter.
2H + O-----> H O
Now it is Balanced!!! Two hydrogen on each side and one oxygen on
each side.
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4 Types of Chemical Reactions
1. Single Replacement Reaction
- Occurs when one element replaces another element in a
compound.
A + BC -----> B +AC
2. Double Replacement Reaction
- Occurs when cations of two compounds switch places.
AB + CD ----> CB + AD
3. Decomposition Reaction
-Occurs when a single compound breaks down into simpler
compounds.
AB -----> A + B
4. Synthesis Reaction
-Occurs when two of more substances combine to form a single
substance.
A + B ----> AB