IONIC COMPOUNDS: Names and Formulas

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IONIC COMPOUNDS Names and Formulas
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Naming compounds in chemistry is called
NOMENCLATURE
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There are a few general rules that apply when
naming ionic compounds. 1. Most ionic compounds
are also called salts. 2. Most ionic compounds
exist as solids and many dissolve to form aqueous
solutions. 3. An ionic compound is made up of a
metal and a nonmetal metals are located on the
left side of the periodic table and nonmetals are
on the right side. 4. The cation (positive ion)
is written first followed by the anion (negative
ion). 5. Before naming compounds, you should
first memorize the individual cations and anions.
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Nomenclature of ionic compounds

• There are two types of ionic compounds depending
  on the cations.
• Type 1 or fixed oxidation state cations only
  form one cation
• Groups IA to IIIA and the elements silver (Ag),
  zinc (Zn) and cadmium (Cd) form only one type of
  ion each
• Group IA elements form 1 ions Li, Na , K
  , Rb , Cs
• Group IIA elements form 2 ions Be 2, Mg
  2, Ca 2, Sr 2, Ba 2
• Group IIIA elements form 3 ions Al 3
• silver ion Ag zinc ion Zn 2 cadmium
  ion Cd 2
• Type 2 or variable oxidation state cations -
  can form multiple cations

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Monatomic Charges
The charge of the individual ions in a salt
should add up to zero, the overall charge of the
compound. For example NaCl is composed of Na
ions and Cl- ions. For every one sodium ion
you need one chloride ion (1) (-1) 0 Ba2
and N3- You need 3 (2 ) Barium ions to cancel
out the 2 (-3) nitride ions so the overall
charge of the compound is zero.
Nomenclature of binary ionic compounds
Name the metal then the root of the nonmetal
ide ending
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Binary ionic compound ROOTS
Symbol Element Root Anion Symbol Anion Name
Br Bromine Brom Br- Bromide
Cl Chlorine Chlor Cl- Chloride
F Fluorine Fluor F- Fluoride
H Hydrogen Hydr H- Hydride
I Iodine Iod I- Iodide
N Nitrogen Nitr N-3 Nitride
O Oxygen Ox O-2 Oxide
P Phosphorus Phosph P-3 Phosphide
S Sulfur Sulf S-2 Sulfide
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Nomenclature of binary ionic compounds
NaCl
BaCl2
Sodium chloride
Barium chloride
H2S
Mg3N2
Hydrogen sulfide
Magnesium nitride
NaF
K2O
Sodium fluoride
Potassium oxide

• Notice that the cation is always mentioned first
  and then the anion.

• Notice that the anion always ends in -ide

• Notice that the number of elements in the
  compound is
• not mentioned in the name.

Name the following ionic compounds
Na2O K2S MgBr2
AlN Ba3As2 CaCl2 AgCl
AlH3 ZnI2 Li3P
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Nomenclature of binary ionic compounds
Answers
Na2O sodium oxide K2S potassium
sulfide MgBr2 magnesium bromide AlN
aluminum nitride Ba3As2 barium arsenide
CaCl2 calcium chloride AgCl
silver chloride AlH3 aluminum
hydride ZnI2 zinc iodide Li3P
lithium phosphide
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Polyatomic Ions
Ions made up of more than one atom are polyatomic
ions The individual ions should add up to the
overall charge of the polyatomic ion. What is
the charge of Mn in MnO4-? 1 Mn 4 O -1
so 1(Mn) 4 (-2) -1 so Mn - 8 -1
so Mn 7 only one polyatomic cation NH4
which is the ammonium ion many polyatomic
anions next page (I will give you a list to
memorize)

• Note the polyatomic ions must be memorized.

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Nomenclature of binary ionic compounds
Some polyatomic anions that you must know NO3-
nitrate NO2- nitrite SO4 2 -
sulfate SO32- sulfite PO43-
phosphate PO33- phosphite CO32-
carbonate HCO31- hydrogen carbonate or
bicarbonate OH- hydroxide CN-
cyanide C2H3O2- acetate C2O42- oxalate
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Nomenclature of binary ionic compounds
Naming salts composed of the polyatomic ions is
the same as with the monatomic anions. Metal
name then polyatomic name.
NaOH sodium hydroxide Ba(NO3)2 barium
nitrate H2SO4 hydrogen sulfate CsNO2
cesium nitrite Sometimes there is a common
name KHCO3 potassium hydrogen carbonate or
potassium bicarbonate
Name the following ionic compounds
NaHCO3 K2SO3 MgSO4
KCN H2PO4 Ca(OH)2 NH4NO3 Zn(NO3)2
Li3PO4 HNO3
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Nomenclature of binary ionic compounds
Answers
NaHCO3 sodium hydrogen carbonate or
sodium bicarbonate K2SO3 potassium
sulfite MgSO4 magnesium
sulfate KCN potassium
cyanide H2PO4 hydrogen
phosphate Ca(OH)2 calcium
hydroxide NH4NO3 ammonium
nitrate Zn(NO3)2 zinc nitrate Li3PO4
lithium phosphate HNO3
hydrogen nitrate
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Early Names of Elements
Present Name Symbol Former Name
Antimony Sb Stibium
Copper Cu Cuprum
Gold Au Aurum
Iron Fe Ferrum
Lead Pb Plumbum
Mercury Hg Hydrargyrum
Potassium K Kalium
Silver Ag Argentum
Sodium Na Natrium
Tin Sn Stannum
Tungsten W Wolfram
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Nomenclature of binary ionic compounds
The previous examples only named type 1 or fixed
oxidation state cations. When naming type 2 or
variable oxidation state cations the rules
change.
CuOH copper(I) hydroxide Fe(NO3)3
iron(III) nitrate CuSO4 copper(II) sulfate
Sn(NO2)4 tin(IV) nitrite Sometimes a common
name exists CuOH cuprous hydroxide
Fe(NO3)3 ferric nitrate

• When naming type 2 cations, the systematic method
  (IUPAC) requires the use of roman numerals after
  the elemental name to represent the oxidation
  state of the cation. The common name uses the
  ic ending for the higher oxidation state and
  ous ending for the lower oxidation state. Many
  times the old latin or greek name is used as the
  root.

Name the following ionic compounds
CuHCO3 FeSO3 CuSO4
Cr(CN)3 Cr(PO4)2 Sn(OH)2
W(NO2)5 Ti(CO3)2 CoPO4
PbCl2
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Nomenclature of binary ionic compounds
Answers
CuHCO3 copper(I) hydrogen carbonate or
cuprous bicarbonate FeSO3 iron(II)
sulfite or ferrous sulfite CuSO4
copper(II) sulfate or cupric sulfate
Cr(CN)3 chromium(III) cyanide Cr(PO4)2
chromium (VI) phosphate Sn(OH)2 tin(II)
hydroxide or stannous hydroxide W(NO2)5
tungsten(V) nitrite Ti(CO3)2 titanium(IV)
carbonate CoPO4 cobalt(III)
phosphate or cobaltic phosphate PbCl2
lead(II) chloride or plumbous chloride
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PRACTICE PROBLEMS
Below the formula, give the systematic name for
the following compounds. If a common name exist,
write it below the systematic name.
1. KBr 2. BaO 3. Na2O 4. CaF3
5. Cr2S3 6. Ti(NO3)4   
potassium bromide
Sodium oxide
Barium oxide
calcium fluoride
Titanium (IV) nitrate or titanic nitrate
Chromium (III) sulfide
The problem set continues on the next page.
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PRACTICE PROBLEMS
Below the name, write the formula for the
following compounds.
Lithium chloride b) Aluminum sulfide e)
Copper(II) oxide f)   Iron(III) chloride
i) Calcium bicarbonate l Potassium
nitrite Potassium sulfate Ammonium
carbonates s )Iron(II) phosphate w)
Li Cl - LiCl
Al3 S2- Al2S3
CuO
Ca(HCO3)2
FeCl3
KNO2
K2SO4
(NH4)2CO3
Fe3(PO4)2