Unit 3 Part 5
Nomenclature
Nomenclature
 IUPAC Naming System (Nomenclature)
 IUPAC =
__ __ __ __ __ __ __ __ __ __ __ __ __
__ __ __ __ __ __
__ __ __
abcdefghijklmnopqrstuvqxyz
__ __ __ __ __
__ __ __ __ __ __ __ __ __
Nomenclature (Ionic)
 For compounds that do not contain polyatomic ions:
 We first write the metal, then the non metal with “ide”
added on.
Ex.
 Li2S=
 AlCl3=
 MgO=
Nomenclature (Ionic)
 When naming ionic inorganic
compounds we always write the metal
first (or the cation) and then the nonmetal (or the anion).
Nomenclature (Ionic)
 For compounds that do contain polyatomic ions:
 We write the metal then the polyatomic ion (do not
add the “ide” ending)
Ex.
 K3PO4=
 (NH4)2CO3=
 Na2SiO3=
 MgSO4 =
Nomenclature (Ionic)
Transition Metals
 When the metal involved in the ionic bond has more
than one oxidations state/possible charge we need to
identify which ion it is. This usually occurs with the
transition metals. Any ion that appears on your
common ion sheet more than once is one of these
types of metals. There are 2 ways to do this.
Nomenclature (Ionic)
 The first way (the way that is the newer
and preferred method) is to use roman
numerals to identify which ion it is.
Nomenclature (Ionic)
 Ex. Fe(CN)3= First we need to find what charge iron has
(Since cyanide has -1 charge and there are 3 of them, iron
must have a 3+ charge). We would then use the roman
numeral III to identify this ion.
 The rules are the same as above but now we add the
roman numeral in the middle.
 The compound Fe(CN)3 would be named:
Nomenclature (Ionic)
 The second way to identify the ion is to use the -ous or
-ic endings.
 The ion with the lower oxidation state (or lower numerical
charge ignoring the + or -) gets the –ous ending, and the ion
with the higher oxidation state gets the –ic ending.
 So in the example above, Iron 3+ is the iron ion with
the higher oxidation state (the other ion is iron (II) ) so
it would get the _____ending. Notice that on your table
of common ions, Iron (III) also has the name _______.
So Fe(CN)3 would be named ferric cyanide.
Nomenclature (Ionic)
(See Naming Ionic
Compounds Assign
Pg. 44)
Writing compounds (from names)
 Just work backwards (and Use Criss Cross):
 Ex. Magnesium Chlorite
 Ex. Lead (II) Iodide
Naming Covalent Compounds
 Binary compounds: These are compounds that
contain only ___ elements. When naming binary
COVALENT compounds we use prefixes to indicate the
amount of each element present.
1
2
mono di
3
4
5
6
7
8
9
10
tri
tetra
penta
hexa
hepta
octa
nona
deca
Naming Covalent Compounds
We rarely use mono, because
normally we just assume that there
is one if no prefix is present. Mono
is only used for oxygen.
Examples
 CO2
 P4O10
 SO3
 N 2O 4
Write Chemical Formula from Name:
 Work Backwords:
 Dinitrogen trioxide
 Diphosphorus pentoxide
Assignments
Pg 44, 45, 46.
Naming Acids
 Naming acids that are binary:
 These would be covalent molecules that
contain a hydrogen and another molecule
(Usually a halogen or sulpfur or phosphorus)
 H__
 Hydro______ic Acid
Examples
 HI
 Hydrochloric acid
Naming Acids
 Naming Acids that are polyatomic:
 These are covalent molecules containing hydrogen and
a polyatomic ion.
 First we need to point out a pattern that you may or
may not have already recognized:
Naming Acids
 There are many sets of polyatomic ions that are similar
to each other where the only difference is the number of
oxygen atoms.
 The ions with more oxygens get an “ate” ending and
the ion with less oxygens gets an “ite” ending.

Ex. Phosphate PO43- and Phosphite PO33Nitrate: NO3- and Nitrite: NO2-
Naming Acids
 The Oxygen containing polyatomic ions are named
as follows:
 Least Oxygens: hypo_____ite
______ite
______ate
Most Oxygens: per_______ate
 These are the polyatomic ions that are involved in acids
Naming Acids
 When naming acids containing polyatomic
ions we name them first by writing the
name of the ion.
 We change the ending. If the ion ends in -ate we
put an –“ic acid” on it. If the ion ends in ite we
put an –“ous acid” ending on it.
Examples
 Ex. H3PO3 ______________________ is the polyatomic
ion in this acid, so the name is
______________________.
 Ex. HClO3: ClO3 is ______________________. Since it
has an ate ending we name it ______________________.
Examples
 Ex. Iodic acid. This has an ic ending so the ion must have an
____________ ending. Iodate (IO3-). Then we add however
many ___________________we need to make the molecule
neutral. So this molecule needs ______________________
hydrogens.
 ______________________ (We write the hydrogen first,
then the polyatomic ion)
 Ex. Chlorous acid. This has an ous ending so we are looking
for an ion with an _________ (with chlorine and oxygen).
Chlorite (ClO2-). We add however many hydrogens we need.
 HClO2
Important:
 Note: On exams and assignments where naming is
required, it is important that you are able to
identify acids and name them appropriately. For
example you name HCl hydrochloric acid, not
hydrogen chloride.
Assignment
 Page 47
Naming Organic
 IUPAC Naming System
 Organic compounds are those which
contain carbon (excluding oxides and
carbonates).
Naming Organic
Types of Hydrocarbons:
 Things to know for naming:
 Alkanes are organic compounds that contain only single
bonds,
 Alkenes are carbon compounds that contain one or more
double bonds
 Alkynes are organic compounds that contain one of
more triple bonds.
Naming Organic
 All Alkanes follow the CnH2n+2 rule.
 All Alkenes containing one double bond between
carbons follow the CnH2n rule.
 These rules will help you to determine whether a
molecule is an alkane, or an alkene.
Naming Organic
 Ex. CH4 is an Alkane because if n=1, then the
molecule would be C1H2(1)+2, Which is CH4.
 Is C2H6 and alkane or alkene?
 Is C2H2 an alkane or an alkene?
 Is C3H6 an alkane or alkene?
Naming Organic
 Prefixes
 When naming organic compounds we must first find
the longest chain of carbons in the molecule. Each
number of carbons in the chains corresponds to a
different prefix.
Number of
Carbons
Prefix
6
Hex
Eth
7
Hept
3
Prop
8
Oct
4
But
9
Non
5
Pent
10
Dec
Number of
Carbons
Prefix
1
Meth
2
Naming Organic
 Suffix
 If the molecule contains all single bonds the suffix is
“ane”. If the molecule contains a double bond the
suffix is “ene”. If the molecule contains a triple bond
the suffix is “yne”.
Examples
Alkenes and alkynes are named using a number to indicate
where the double or triple bond is located. Always number
the carbons so that you get the lowest possible number.
Examples

 If the Compound contains 2 or more double bonds you
would need to use di, tri etc.
 Ex. 1,2 butadiene or buta-1,2-diene

Alkyl Groups
 If you remove a hydrogen atom from one of these
carbon chains and add a branch, you get an alkyl
group. These are also named based on the number of
carbons but the suffix is “yl”
 For example methyl –CH3. These alkyl groups can then
bond with another compound in place of a hydrogen.
Alkyl Groups
 To name these we first identify the longest carbon
chain. Next number the carbons. To write the name we
first write the number, then the name of the alkyl
group, then the name of the longest carbon chain.
 # - alkyl group longest carbon chain
Alkyl Groups
 # - alkyl group longest carbon chain
 Ex 5.
Alkyl Groups
 When naming compounds with more than one alkyl
group, you must name them alphabetically. You also
number the carbons so that the first group in the name
has the lowest number.
Alkyl Groups
 If you have two of the same alkyl group you name
them as follows:
 #, # - dialkyl group longest carbon chain
 If you had three of the same alkyl groups you would
use 3 numbers to indicate where they are located and
the prefix tri on the name of the alkyl group.
Alkyl Groups
Alkyl Groups
 Ex 8. 2-methylpropane
 Ex 9. 3, 3- diethyl hexane
Line Forms

= Propane

= 3-methyl pentane

= Propene
Draw the molecules from examples 1-9 in line
form: