Download How to Name Chemical Compounds

How to Name Chemical Compounds
In order to apply the proper
nomenclature to chemical
compounds, the compound itself
needs to be identified as to type or
class
Question #1
What type of compound is it?
Ionic?
Molecular?
- Organic?
Acid?
Hydrate?
Identifying the Compounds
Ionic – usually a compound composed of a metal &
a nonmetal; a metal & a polyatomic anion; a
polyatomic cation and a nonmetal; or a polyatomic
cation & a polyatomic anion.
Molecular – usually a compound composed of two
nonmetals
-organic compound (one containing carbon
and frequently hydrogen; excludes CO, CO2,
and carbonates)
Identifying the Compounds
Inorganic acids – these compounds contain
hydrogen available for donation in a chemical
reaction; their formulas generally start with H
(hydrogen) and are followed by a nonmetal or
polyatomic anion
Hydrated compounds – these compounds appear as
a salt or ionic compound with water molecules
attached; meaning there is a dot (•), possibly a
numerical coefficient, and the formula of water,
H2 O
Ionic Compound - Question #1
What is the positive ion?
Metal from Group 1 (IA), Group 2 (IIA),
Group 13 (IIIA) {first three elements} or Zn,
Cd, or Ag?
A metal not found in Group 1 (IA), Group 2
(IIA), Group 13 (IIIA) {first three elements} or
Zn, Cd, Ag?
A positive polyatomic ion?
Naming Positive Ions
For metals from Group 1 (IA), Group 2 (IIA), or
Group 13 (IIIA) {first three elements} Zn,
Cd, or Ag
Write the name of the
metallic element
Naming Positive Ions
For metals NOT found in Group 1 (IA), Group 2 (IIA),
Group 13 (IIIA) {first three elements} or Zn, Cd, Ag
Traditional name – apply an “-ic” suffix to the ion of
greater charge and an “-ous” suffix to the ion of
lesser charge.
Stock System name – place a Roman numeral in
parentheses, ( ), immediately after the element’s
name. The Roman numeral indicates the charge on
the metal ion in that compound.
Identifying the Charge on the Cation
In order to apply the Stock or traditional name,
the charge on the metallic cation must be
determined.
How????
1) Determine total negative charge in
formula of the compound
2) Recognize, there is equal positive charge
3) Divide the positive charge by number of
metal ions
Naming Positive Ions
For polyatomic cations
Write the polyatomic ion’s name
Ionic Compounds - Question #2
What is the negative ion?
Nonmetal – elements located to the right of the
staircase on the periodic table
A negative polyatomic ion
Naming Negative Ions
For a nonmetallic anion – modify the name of the
nonmetallic element with the attachment of an
“-ide” suffix
For a polyatomic anion -
Write the name of the polyatomic
ion.
Molecular Compound – Question #1
Are you using the traditional or the Stock
naming system?
Traditional Naming of Molecular
Compounds
Attach a prefix to the name of each element that
indicates the number of atoms of that element
present in a molecule of the compound.
In ADDITION, modify the more negative element’s
name for the attachment of the “-ide” suffix
Note: The more negative element has
greater electronegativity or ionization energy
A Reminder
The “mono-” prefix is usually dropped
from the more positive element
Stock System Name of Molecular
Compounds
Represent the “apparent charge” of the more
positive element with a Roman numeral in
parentheses.
Note: The more positive element has
lower electronegativity or ionization
energy.
In ADDITION, modify the more negative element’s
name for the attachment of the “-ide” suffix
Molecular Naming Confusion…..
When naming molecular compounds,
name using the traditional system or the
Stock system, but NOT a combination or
hybrid of both systems!!!!
Organic Compounds
What type of organic compound is it?
Alkane
CnH2n+2
Alkene
CnH2n
Alkyne
CnH2n-2
Alcohol
R-OH (where R is any alkyl group)
Prefixes are determined based upon
number of carbon atoms
MethEthPropButPentHexHeptOctNonDec-
1
2
3
4
5
6
7
8
9
10
Naming Alkanes
In order to name an alkane, determine the
number of carbon atoms in the chain and select
the correct prefix.
Attach the suffix “-ane” to the prefix.
CH4 – methane
C2H6 - ethane
Naming Alkenes
In order to name an alkene, determine the
number of carbon atoms in the chain and select
the correct prefix.
Attach the suffix “-ene” to the prefix.
If the double bond is not on a terminal carbon,
use a number and dash to indicate its position in
the molecule so the smallest number is used.
Naming Alkenes
C2H4 – ethene
3-heptene
Naming Alkynes
In order to name an alkyne, determine the
number of carbon atoms in the chain and select
the correct prefix.
Attach the suffix “-yne” to the prefix.
If the triple bond is not on a terminal carbon,
use a number and dash to indicate its position in
the molecule so the smallest number is used.
Naming Alkynes
C2H2
ethyne
2-hexyne
Naming Alcohols
In order to name an alcohol, determine the
number of carbon atoms in the chain and select
the correct prefix.
Attach the suffix “-anol” to the prefix.
If the –OH (hydroxyl group) is not on a terminal
carbon, use a number and dash to indicate its
position in the molecule so the smallest number
is used.
Naming Alcohols
CH3OH
methanol
2-butanol
Acids – Question #1
Is the acid a binary acid/nonoxyacid; or is it an
oxyacid?
Oxyacid – contains hydrogen combined
with an oxyanion
Binary acid – contains hydrogen and a
nonmetal
Nonoxyacid – contains hydrogen and other
polyatomic anion
Binary or Non-oxyacids Acids
The form for naming a binary or
non-oxyacid is
hydro – root of nonmetal/anion - ic
Naming an Oxyacid
The form for naming an oxyacid is
Anion prefix - anion root - (-ic)/(-ous)
If the polyatomic anion has a prefix
(e.g. per- or hypo-) it is retained.
What about - ic and – ous?
If the oxyanion ends with an “-ate,”
the “–ate” is replaced by the “-ic”
suffix.
If the oxyanion ends with an “-ite,” the
“-ite” is replaced by the “–ous” suffix.
Hydrated Compounds Question #1
What is the ionic compound or salt to which
water is attached?
Identify the ionic compound (salt) and name
according to the rules discussed under ionic
nomenclature
Hydrated Compounds – Question #2
How many waters are attached to EACH formula
unit of the ionic compound or salt?
Look at the numerical coefficient of water
Attach a prefix to the term “–hydrate”
to indicate the number of waters
present per formula unit.
Prefixes to attach to hydrate
Prefixes to attach to hydrate in indicating waters per formula
unit.
MonoDiTriTetraPentaHexaHeptaOctaNonaDeca-