INORGANIC NOMENCLATURE
-
NAMING
COMPOUNDS
'NORGANIC
Every compound has its own CHEMICAL FORMULA and its own NAME, The
nomenclature (naming systems) for loNlc and covALENT compounds are different.
IONIC COMPOUNDS:
These consist of any positive ion (except H-) combined with any negative ion. (lf H. is
the positive ion, the compound is an acid, as we will see later on page 6.)
* The positive ion (cation) may be a metal ion (such as Na* ) or a polyatomic ion
(such as NHo ).
+ The negative ion (anion) may be a non-metal ion (such as Cl-) or a polyatomic ion
(such as SOf- or NO. ).
1. lonic compounds: Representative
Case
Examples: KBr potassium
Note
bromide AlCl.
lliletal + Non-Metal
aluminum
chloride Li,N
lithium nitride
1:
Metal is always first (name unchanged), non-metal second (the ending of the
non-metal is dropped, and the -lDE ending is added).
Note 2: The name does not indicate how many of each.
Exercise: Write formulas for the followinq cations:
barium ion
potassum
aluminum ion _
Exercise: Write formulas for the following anions:
bromide
_
nitride
iodide
ion_
radium ion
oxide
sulfide
Exercise: Name the following:
NaF
Mgs
rl,
Ca.N,
K.o
Al2o3
S
Ba,N,
Na.P
Exercise: Give formulas for the following compounds (refer to periodic table only).
cesium phosphide
_
magnesium nitride
_
calcium iodide
aluminum
bromide
barium fluoride
sodium selenide
Case
2. lonic Compounds: Transition
Metal + Non-Metal
In general, it is Nor possible to use the periodic table to predict what ions are formed
by transition metals. You have to LEARN the formulas for the ions of those
transition elements that were assigned in lecture.
+
lf the transition metal forms only one ion, name the compound as in case 1.
Examples: ZnCl, zinc chloride; AgrS silver sulfide; NiF, nickel fluoride;
+
lf the transition metal forms two ions, the naming system is as follows:
Old system: -ous ending refers to the ion with lower charge.
-ic ending refers to the ion with higher charge.
ferrous
Cu" cuprous
ferric
Cu2* cupric
Sn2* stannous Sna* stannic
Fe2'
Cf'
Fe3'
chromous
Cf.
chromic
Hgr*2 mercurous Hg2* mercuric
pb2t plumbous pbl*
plumbic
Modern (stock) system : A Roman numeral after the metal name indicates the charge
on the metal ion.
Examples: Fe3- is iron
Sna. is tin
Cu. is copper (l)
(lll)
*
(lV)
Note; The charge on a iransition metal ion can be determined from its compound.
Examples: In FeF, there are 2 F'so it's Fe'2 Name: ferrous fluoride or iron(ll) fluoride
In FerO, there are 3 02- so here the ion is Fe*3 Name: ferric oxide or iron (lll) oxide
* Note: You must be able to give the modern (stock) name and the old name for each
compound.
Exercise: Name the following compounds (two names if applicable):
AgCl
FeBr.
Cu,N
CrrS.
Exercise: Give formulas for the followinq comoounds:
chromium (lll) oxide
zinc nitride
_
stannous
cupric bromide
fluoride
ferrous iodide
cobalt ( ll) oxide
Case 3. lonic Compounds with Polyatomic lons"
Cases 1 and 2 above involve ionic compounds that consist of a metal cation and
a non-metal anion---two elements only. These are called binary compounds_
Now let us turn to ionic compounds that are formed from polyatomic ions:
You must learn the names and formulas for all the polyatomic ions assigned in lecture.
To the list of polyatomic ions given in the text, add CrOo'- (oxalate).
*
As wilh all ionic compounds, the cation is named first, then the anion:
Examoles:
(NH4)rS
Zn(NO.),
CuCO.
+
sulfide
nitrale
ammonium
K3PO4 potassium phosphaie
zinc
Fer(SOo). ferric sulfate or iron (lll) sulfate
cupric carbonate or copper (ll) carbonate
Note: Parentheses ( ) are used only when there are 2 or more polyatomic ions.
Exercise: Name the following:
(NH4)ro
NarSO.
FeCrO,
or
CuNO,
Znr(POo),
Ca(HSOo),
Sn(NOr),
or
Exercise: Give formulas for the following:
cupric nitrate
silver carbonate
barium permanganate
nickel hydroxide
potassium dichromate
lithium phosphate
chromous hvdroxide
mercuric cyanide
magnesium bicarbonate
aluminum hydrogen sulfate
COVALENT COMPOUNDS
when non-metal atoms share electrons with other non-metal atoms, they form covalent
(molecular) compounds. we shall learn the nomenclature of binarv covalent
compounds.
Exercise: Define a binary compound
Case
*
*
4.
Binary Covalent Compounds
As with ionic compounds, the more negative atom is last and gets an -lDE ending.
Unlike ionic compounds, the number of each atom is specified with a prefix.
These are the prefixes you need to know:
1 is
2 is
3
6 is
7 is
8
monohexa-
+
dihepta-
is
is
tri-
octa-
4 is
9 is
tetranona-
S is penta_
10 is deca-
Note: when there is only one atom of the first element, the mono prefix is omitted.
Examples:
NF.
nitrogen kifluoride
PoO,'o tetraphosphorus
decaoxide
lrS
diiodinemonosulfide
B,Cl^ diboron hexachloride
Exercise: Name the followino:
NrO,
PCl5
SO,
SO,
CS,
BrrO,
co
Pro.
cl2o
JFa
Exercise: Give formulas for the following:
_chlorine dibromide orygen difluoride
carbon tetrachloride _
sulfur hexafluoride silicon dioxide
iodine heptafluoride _
nitrogen monoxide dinitrogen trioxide
iodine pentabromide
*
AIso: you must remember these three very important common names:
HrO (water)
NH, (ammonia)
CHo {methane)
Case
5.
Diatomic Molecules
Several common non-metal elements exist as diatomic molecules. The name of the
element refers to the diatomic molecule. For example, "hydrogen' refers to H, and
"oxygen' refers to Or. (lf we mean the atom, we say atomic hydrogen or atomic
orygen). The common diatomic elements are the four halogens, oxygen, nitrogen, and
nyorogen.
Exercise: List the names and formulas of the 7 elements that exist as diatomic
molecules:
Exercise: Write the following sentences using symbols and formulas instead of the
underlined names of the gases.
Dry air contains about 79% nitrogen and 21% oxygen, with small amounts of carbon
dioxide, neon, and argon. Polluted air may contain small amounts of sulfur dioxide,
sulfur trioxide, nikogen dioxide, dinitrogen monoxide, chlorine, ammonia, methane, and
carbon monoxide.
Exercise: Write the following sentences using names instead of symbols and formulas.
Probably the most important element found uncombined in nature is Or. O, is quite
reactive, forming compounds with the halogens F 2, Cl2 , Br, and lr. O, forms two
compounds with H2. Following the usual rules of nomenclature, the most common
oxide of hydrogen (HrO) would be named dihydrogen monoxide. The other oxide of
hydrogen is HrOr. O, forms a series of compounds with N, , many of which are
atmospheric pollutants, including NO NrO NO, N2O1 . N2O5.
,
,
,
Case
6.
ACIDS
As a group, ACIDS are a separate category from ionic compounds and covalent
compounds. Acids consist of hydrogen ion, Ht , and a anion. The naming system for
acids is different from that of other ionic or covalent compounds. we will not consider
those systems at this time.
Some acids, called slrong acids, are ionic. These acids are used in industry and in the
laboratory. You must learn the narnes and formulas of the three common strono acids:
HCI
hydrochloric acid
HrSOo sulfuric acid
HNO3 nitric acid
Other acids, called weak acids, are partly ionic and partly covalent. All the acids found
in food are weak acids. Learn the names and formulas of these common weak acids:
HC2H3O2 acetic acid
H3PO4
H2CO3
H2C2A 4
phosphoric acid
carbonic acid
oxalic acid
Exercise: Write formulas for the underlined acids in the following sentences:
In industry, hydrochloric acid is known as muriatic acid and is used in concrete
work. Since sulfuric acid is used in automobile bafteries, it is commonly called battery
acid. Nitric acid is probably the most common oxidizing agent used in laboratories.
Acetic acid is the acid in vinegar. Phosphoric acid and carbonic acid are added to soft
drinks to provide a pleasantly tart taste. Oxalic acid is found in many plants, including
rhubarb and spinach. A high concentration of this acid is toxic.
e
xercises ior f urtn
Name the following:
NarSOu
jt3 rr*
'
Fe{NOu),
ol
Pb02
A
rrl lil
(N'd4)2020"'
FtNOs
CuCrOo
PbCr,O,
or
Sel,
CUHPO
or
SF+
-----=
H Yvr2
or
B rzO-
KCtO
Sn(ClOr),
NaHrPOo
nr
Give Formulas for the Followinq.
zinc phosphate
stannous hydroxide
ammonium nitrite
vuPr ru oulr
iiihir-im si"ilfiie
siiver-dichrornate
sulfui trioxide
suiiuric acicl
nickel chlorate
chromic bromide
ferric chromate
bromine
skontiurn nitrate
iron ( ll) hydroxide
calcium carbonate
ammonium sulfite
cupric phosphide
lead (lV) sulfide
plumbic acetate
potassium dichromate
tiianium (lV) chloride
chromous oxide
diboron hexafiuoride
cobalt ( ll) bromide
aluminum dihydrogen phosphate
magnesium carbonate
strontium sulfite
orygen difiuoride
phosphoric acid
nitrogen
t
cn
v
calcium hvdroxide
ammonium oxalate
sodium hypochlorite
magnesium nitrate
ferric cyanide
silver phosphate
potassium permanganate
ferrous hydrogen sulfate
zinc sulfide
carbonic acid
plumbous bicarbonate
gold (lll) bromide