Chapter 7
Nomenclature
CHM130
GCC
Nomenclature
• We will be presenting this chapter a bit
different than the text book does. The
information is the same, so reading the
text is still a good idea. But take an
especially careful look at the online notes
for this chapter. Good luck! 
Terms
• Ionic compound = metal + nonmetals
• Covalent compound = nonmetals only,
(aka molecular)
• Monoatomic ion = one atom w/charge
– Na+, Cl-, Ca2+
• Polyatomic ion = two or more atoms
w/charge (listed on your Periodic Table –
become familiar with them)
– PO43-, OH-, CO32-
Element Names
• Know the names for elements 1-20 AND
– Barium Ba
– Cobalt Co
– Iodine I
– Copper Cu
– Iron Fe
– Lead Pb
– Mercury Hg
Silver Ag
Gold Au
Zinc Zn
Tin Sn
Strontium Sr
Nickel Ni
Bromine Br
Ionic Compounds
• We will begin by learning formulas and
names for ionic compounds
• Remember that ionic compounds are
made of ions, and ions have a charge
• The sum of the charges must = zero
Oxidation States
• Is a fancy name for charge
• All elements have a charge of zero when
they are alone (elemental state)
• Elements have a charge when they have
lost or gained electrons
– Some elements have a fixed charge – only
one possibility
– Other elements have variable charge –
several possibilities
Cations
• Metals lose electrons to be cations (+)
• Charges (learn these)
– Column IA is always +1 (alkali metals)
– Column IIA is always +2 (alkaline earth metals)
– Column IIIA is often +3 (Al always)
– Zn and Cd always +2
– Silver always +1
– Other metals can vary from +1 to +9 so use
Roman Numeral to tell the difference like Cu+2
is copper(II), Fe+3 is iron(III), Pb+4 is lead(IV)
Anions
• Nonmetals gain electrons to be anions (-)
• Charges (learn these)
– Column 5 is –3 usually
– Column 6 is –2 usually
– Column 7 is –1 usually (F always)
– Column 8 is 0 Why???
Noble gases are already happy with 8
outer valence electrons (He has 2) so
don’t need to form bonds – they don’t
want to gain or lose electrons!!!
7.3 Polyatomic Ions
• Check out information on your periodic
table
• Keep these atoms together as a group,
think of them as a group, a single entity
Formulas of Ionic Compounds
• Compounds MUST be neutral
• Need enough cations and anions to = zero
• Combine Na and N: Na is +1 and N is –3 so need
three Na’s for one N so Na3N is the formula
• What is the formula?
–
–
–
–
–
–
–
Na and S
Mg and O
K and Br
Ca and N
Al and Cl
Zn and I
Cu(II) and O
Na2S
MgO
KBr
Ca3N2
AlCl3
ZnI2
CuO
Formulas with Polyatomic Ions
• What is the Formula?
– Mg and OH– K and PO43– Ag and SO42– Ca and NO3– Cu(II) and CO32– Pb(IV) and O
Mg(OH)2
K3PO4
Ag2SO4
Ca(NO3)2
CuCO3
PbO2
Naming Ionic Compounds
• Now that you can write ionic compound
formulas, we need to learn their names
• The name depends on whether the metal has a
fixed or variable charge
• For a fixed charge metal, like Na, we KNOW the
charge so don’t use Roman numerals
• For a variable charge metal, like Cu, we don’t
know the charge so we do use Roman numerals
• Check it out…
Fixed charge metal ionic compound
• Metal name + nonmetal + “ide”
– NaCl sodium chloride
What is the name?
– KBr
– MgO
– CaF2
– Li2S
– AgCl
Potassium bromide
Magnesium oxide
Calcium fluoride
Lithium sulfide
Silver Chloride
– Note the ionic name does NOT indicate
how many atoms there are
Names with Polyatomic Ions
• Do NOT change the polyatomic ion name
– NaNO3 sodium nitrate
What is the name?
– K3PO4
Potassium phosphate
– Ca(OH)2
Calcium hydroxide
– ZnSO4
Zinc sulfate
Variable charge Metal Ionic Compound
• Metal name (Roman #) + nonmetal + “ide”
• YOU must figure out charge on Trans metal
– CuCl2 copper(II) chloride (Cu must be +2 since Cl is –1
and there are two of them)
What is the name?
– PbO2
Lead(IV) oxide
– FeBr3
Iron(III) bromide
– CoSO4
Cobalt(II) sulfate
– HgNO3
Mercury(I) nitrate
– CoN
Cobalt(III) nitride
• YOU must figure out the formula AND
the name for ionic compounds.
• Name only for covalent compounds
(Why? They don’t have ions so you
can’t add to zero)
• Example: K and O
– You figure out formula: K2O
– You figure out name: Potassium oxide
Covalent / Molecular Compounds
• Compounds with only nonmetals
• These are NOT ions, so no charges
• Use prefixes
–
–
–
–
mono
di
tri
tetra
-penta
-hexa
-hepta
-octa
• Prefix + nonmetal name + prefix + 2nd nonmetal
name + “ide”
• Don’t use mono for the 1st nonmetal
Examples
• CO2 is carbon dioxide
What is the name?
Carbon monoxide
• CO
Diphosphorus pentoxide
• P2O5
Phosphorus trifluoride
• PF3
Iodine heptafluoride
• IF7
Given the formula, write the
name and vice versa
•
•
•
•
•
•
Br3O8
P4S7
SO3
Iodine hexafluoride
Dichlorine pentaoxide
P2I4
Tribromine octaoxide
Tetraphosphorus heptasulfide
Sulfur trioxide
IF6
Cl2O5
Diphosphorus tetraiodide
Reminders
• Prefixes are ONLY with covalent
compounds
• Roman Numerals are ONLY with variable
charged metal compounds
• Polyatomic ions NEVER change their
name
Acids
•
•
•
•
Compounds that lower pH in water
Have H+ ions in them
Dissolved in water = (aq)
You should memorize these 6 acids
–
–
–
–
–
–
HCl(aq)
HF(aq)
H2SO4 (aq)
H3PO4 (aq)
HNO3 (aq)
H2CO3 (aq)
hydrochloric acid
hydrofluoric acid
sulfuric acid
phosphoric acid
nitric acid
carbonic acid
What the
heck is (aq)?
Write the formula or name for
each – you have 3 minutes!
•
•
•
•
•
•
BaCl2
NO2
Fe3(PO4)2
Diiodine tetraoxide
Silver sulfate
Nickel(III) sulfide
Barium chloride
Nitrogen dioxide
Iron(II) phosphate
I2O4
Ag2SO4
Ni2S3
• Do the chapter 7 worksheet posted on this
practice problems web page
• Seriously – JUST DO IT
• http://web.gccaz.edu/~ksmith8/rev130.htm
Self Test
Page 196
Try 4, 6, 9, 11
Answers in Appendix J