Unit 5: Bonding and Inorganic Nomenclature
Name: ____________________
Chemical Bonding
Ionic Bonds: species give up or gain e– and are attracted
to each other by coulombic attraction
ionic compounds = salts
where NO3– is a polyatomic ion:
oxyanions: polyatomic ions containing oxygen
“Most common” oxyanions:
BrO3–
ClO3–
PO43–
IO3–
NO3–
SO42–
CO32–
If an oxyanion differs from the above by the # of O atoms, the name changes are as follows:
EX.
one more O
=
per_____ate
“most common” # of O
=
_____ate
one fewer O
=
_____ite
two fewer O
=
hypo_____ite
Name the following ions.
SO32–
BrO–
NO2–
ClO4–
The “most common” oxyanions previously mentioned should be memorized. You should
memorize the following as well:
OH–
CH3COO–
CrO42–
CN–
NH4+
Cr2O72–
Properties of Ionic Compounds (i.e., of Salts)
1. very hard –
2. high melting points –
3. brittle –
1
MnO4–
…atoms share e– to get a full valence shell
Covalent Bonds
covalent compounds = molecular compounds
-- have lower melting points than do ionic compounds
In metals, valence shells of atoms overlap, so v.e–
Metallic Bonds
are free to travel between atoms through material.
Properties of Metals
Writing Formulas of Ionic Compounds
chemical formula:
To write an ionic compound’s formula, we need:
1. the two types of ions
2. the charge on each ion
EX.
Na+
and
Ba2+
and
F–
Na+
O2–
and
Ba2+
and
O2–
F–
charge on cation / anion “becomes” subscript of anion / cation
criss-cross rule:
** Warning:
EX.
Al3+ and O2–
In3+ and Br–
Ba2+ and S2–
Compounds Containing Polyatomic Ions
Parentheses are req’d only when you need more
than one “bunch” of a particular polyatomic ion.
EX.
Ba2+
and
SO42–
Sn4+
and
SO42–
Mg2+
and
NO2–
Fe3+
and
Cr2O72–
NH4+
and
ClO3–
NH4+
and
N3–
2
Inorganic Nomenclature
Ionic Compounds (cation/anion combos)
Fixed-Charge Cations with Elemental Anions
The fixed-charge cations are:
A. To name, given the formula:
1. Use name of cation.
2. Use name of anion (it has the ending “ide”).
EX.
NaF
Na2O
BaO
BaF2
B. To write formula, given the name:
1. Write symbols for the two types of ions.
2. Balance charges to write formula.
EX.
silver sulfide
zinc phosphide
calcium iodide
Variable-Charge Cations with Elemental Anions
The variable-charge cations are:
A. To name, given the formula:
1. Figure out charge on cation.
2. Write name of cation.
3. Put Roman numerals in ( ) to show
cation’s charge.
4. Write name of anion.
EX.
FeO
CuBr
Fe2O3
CuBr2
B. To find the formula, given the name: 1. Write symbols for the two types of ions.
2. Balance charges to write formula.
EX.
cobalt(III) chloride
tin(IV) oxide
3
tin(II) oxide
Compounds Containing Polyatomic Ions
Insert name of ion where it should go in the compound’s name.
EX.
EX.
Write formulas:
ammonium chlorate
iron(III) nitrite
zinc phosphate
ammonium phosphide
lead(II) permanganate
Write names:
(NH4)3N
(NH4)2SO4
U(CrO4)3
AgBrO3
Cr2(SO3)3
Covalent Compounds -- contain two types of nonmetals
** Key:
What to do:
EX.
Use Greek prefixes to indicate
1–
6–
how many atoms of each element,
2–
7–
but don’t use “mono” on first element.
3–
8–
4–
9–
5–
10 –
carbon dioxide
N2O5
CO
carbon tetrachloride
dinitrogen trioxide
NI3
Acid Nomenclature
binary acids: acids w/H and one other element
Binary Acid
Nomenclature
1. Write “hydro.”
2. Write prefix of the other element, followed by “-ic acid.”
HCl
hydroiodic acid
HBr
hydrosulfuric acid
4
oxyacids: acids containing H, O, and one other element
Oxyacid
Nomenclature
For “most common” forms of the oxyanions, write prefix of
oxyanion, followed by “-ic acid.”
HClO3
sulfuric acid
H2CO3
phosphoric acid
If an oxyacid differs from the above by the # of O atoms, the name changes are:
one more O
=
per_____ic acid
“most common” # of O
=
_____ic acid
one fewer O
=
_____ous acid
two fewer O
=
hypo_____ous acid
HClO4
HClO2
phosphorous acid
HClO3
HClO
hypobromous acid
Traditional (or Latin) System of Nomenclature
…used historically (and still some today) to name compounds w/variable-charge cations
To use:
1. Use Latin root of cation.
2. Use -ic ending for higher charge; -ous ending for lower charge.
3. Then say name of anion, as usual.
EX.
Element
Latin root
-ic
-ous
gold, Au
aur-
Au3+
Au+
lead, Pb
plumb-
Pb4+
Pb2+
tin, Sn
stann-
Sn4+
Sn2+
copper, Cu
cupr-
Cu2+
Cu+
iron, Fe
ferr-
Fe3+
Fe2+
Write formulas:
Write names:
cuprous sulfide
Pb3P4
auric nitrite
Pb3P2
ferrous fluoride
Sn(OH)4
5
Empirical Formula and Molecular Formula
Compound
Molecular Formula
glucose
C6H12O6
propane
C3H8
butane
C4H10
naphthalene
C10H8
sucrose
C12H22O11
octane
C8H18
6
Empirical
Formula