Names and formulas of inorganic compounds, organic compounds, cyclic compounds. Binary compounds of two nonmetals. Functional groups.

1. Naming Chemical
Compounds
Dr. K. Shahzad Baig
Memorial University of Newfoundland
(MUN)
Canada
Petrucci, et al. 2011. General Chemistry: Principles and Modern Applications. Pearson Canada Inc., Toronto, Ontario.
Tro, N.J. 2010. Principles of Chemistry. : A molecular approach. Pearson Education, Inc.

2. Naming Compounds:
Organic and Inorganic Compounds
Ca3(PO4)2
“C-A-three-P-O-four-two”
“calcium phosphate.”
they are inconvenient for routine verbal communication
many compounds have the same empirical and molecular formulas but different
arrangements of atoms, which differences result in very different chemical and physical
properties.
In such cases, it is necessary for the compounds to have different names that distinguish
among the possible arrangements.

3. Names and Formulas of Inorganic Compounds
Binary compounds are those formed between two elements
To name a binary compound
of a metal and a nonmetal,
1. write the unmodified
name of the metal
2. then write the name of the
nonmetal,
3. modified to end in –ide

4. Some metals may form several ions, it is important to distinguish between them in
naming their compounds, for example,
𝐹𝑒2+ 𝑎𝑛𝑑 𝐹𝑒3+
𝐹𝑒𝐶𝑙2 𝑖𝑠 𝑖𝑟𝑜𝑛 𝐼𝐼 𝑐ℎ𝑙𝑜𝑟𝑖𝑑𝑒 𝑎𝑛𝑑 𝐹𝑒𝐶𝑙3 𝑖𝑠 𝑖𝑟𝑜𝑛 𝐼𝐼𝐼 𝑐ℎ𝑙𝑜𝑟𝑖𝑑𝑒
to use the –ous ending for the lower oxidation state of the metal and -ic for the higher
oxidation state for naming compound.
FeCl2 is ferrous chloride, and FeCl3 is ferric chloride.
Cu2O and CuO
In Cu2O the O.S. of Cu is +1 and in CuO it is +2
Cu2O is assigned the name cuprous oxide, and CuO is cupric oxide

5. Binary Compounds of Two Nonmetals
When both nonmetals forms a molecular compound.
The method of naming these compounds is similar to that just discussed.
For example,
𝑯𝑪𝒍 , 𝑯𝒚𝒅𝒓𝒐𝒈𝒆𝒏 𝒄𝒉𝒍𝒐𝒓𝒊𝒅𝒆
In both the formula and the name, the element with the positive oxidation state comes
first:
HCl and … not ClH.

6. EXAMPLE 3-8
Write formulas for the compounds barium oxide, calcium fluoride, and iron(III) sulfide.
Write acceptable names for the compounds, Na2S, AlF3, Cu2O

7. Some pairs of nonmetals form more than one binary molecular compound,
and these are distinguish by indicating relative numbers of atoms through prefixes:
mono = 1, di = 2, tri = 3, tetra = 4, penta = 5, hexa = 6, hepta = 7, octa = 8.
NO Nitrogen monoxide
NO2 Nitrogen dioxide
N2O Dinitrogen monoxide
N2O3 Dinitrogen trioxide
N2O4 Dinitrogen tetroxide
N2O5 Dinitrogen pentoxide
CO Carbon monoxide
CO2 Carbon dioxide

8. Binary Acids
A binary acid is a two-element compound of hydrogen and a nonmetal.
Naming of binary acids is done by the formula :
ℎ𝑦𝑑𝑟𝑜 𝑛𝑎𝑚𝑒 𝑜𝑓 𝑛𝑜𝑛 − 𝑚𝑒𝑡𝑎𝑙 − 𝑖𝑐 𝑎𝑐𝑖𝑑
HCl(aq) hydrochloric acid
H2S(aq) hydrosulfuric acid
HI(aq) hydroiodic acid
HBr(aq) hydrobromic acid

9. Polyatomic Ions
3. An element common to many polyatomic anions is oxygen, Such anions are called
oxoanions.
4. Certain nonmetals (such as Cl, N, P, and S) form a series of oxoanions containing
different numbers of oxygen atoms.
Their names are related to the oxidation state of the nonmetal atom to which the O
atoms are bonded, ranging from hypo- (lowest) to per- (highest) according to the
following scheme.
Increasing oxidation state of nonmetal
hypo___ite ___ite ___ate per___ate
Increasing number of oxygen atoms :
1. The most familiar polyatomic cation is the ammonium ion, NH4+.
2. The most familiar polyatomic anion are hydroxide ion , OH - and cyanide ion , CN -

10. Some common polyatomic ions
Hypochlorite ion ClO- NaClO
Chlorite ion ClO2- NaClO2
Chlorate ion ClO3- NaClO3
Perchlorate ion ClO4- NaClO4
Chromate ion CrO4
2- Na2CrO4
Dichromate ion Cr2O7
2- Na2Cr2O7
Nitrite ion NO2- NaNO2
Nitrate ion NO3- NaNO3
Oxalate ion C2O4
2- Na2C2O4
Name Formula Typical Compound

11. SO₄²- 𝑆2 𝑂3
2−
7. The prefix thio- signifies that a sulfur atom has been substituted for an oxygen atom.
(The sulfate ion has one S and four O atoms; thiosulfate ion has two S and three O atoms.)
5. All the common oxoanions of Cl, Br, and I carry a charge of 1-
6. Some series of oxoanions also contain various numbers of H atoms and are named
accordingly.
For example, is the hydrogen phosphate ion and the 𝑑𝑖ℎ𝑦𝑑𝑟𝑜𝑔𝑒𝑛 𝑝ℎ𝑜𝑠𝑝ℎ𝑎𝑡𝑒 𝑖𝑜𝑛.
𝐻𝑂4 𝑃2−
𝐻2 𝑂4 𝑃−
𝑂4 𝑃3−

12. Names and Formulas of Organic Compounds
The great diversity of organic compounds arises from the ability of carbon atoms to
combine readily with other carbon atoms and with atoms of a number of other elements.
Carbon atoms join together to form a framework of chains or rings to which other atoms
are attached
Hydrocarbons
The four major classes of hydrocarbons are the following:
the alkanes, which contain only carbon–hydrogen and carbon–carbon single bonds;
the alkenes, which contain at least one carbon–carbon double bond;
the alkynes, which contain at least one carbon–carbon triple bond; and
the aromatic hydrocarbons, which usually contain rings of six carbon atoms that can be
drawn with alternating single and double bonds.

13. Alkane
Stem Number of
(or prefix) C Atoms
Meth- 1
Eth- 2
Prop- 3
But- 4
Pent- 5
Hex- 6
Hept- 7
Oct- 8
Non- 9
Dec- 10
The names of the alkanes are composed of two parts:
𝑆𝑡𝑒𝑚 𝑤𝑜𝑟𝑑 − 𝑎𝑛𝑒
Methane, CH4
Ethane C2H6
Propane C3H8
Butane C4H10
- - - - - -
CnH2n+2

14. Alkanes with four or more carbon atoms can have more than one arrangement of
atoms.
For example, butane (C4H10) has two possible structures.
Normal butane (usually called n-butane) is CH3CH2CH2CH3,
in which the carbon atoms form a single unbranched chain.
isobutane (2-methyl propane) is (CH3)2CHCH3,
in which the primary chain of three carbon atoms has a one-carbon chain branching
at the central carbon
The systematic names for branched hydrocarbons use the lowest possible number to
indicate the position of the branch along the longest straight carbon chain in the
structure.
Thus the systematic name for isobutane is 2-methylpropane, which indicates that a
methyl group (–CH3) is attached to the 2nd carbon of a propane molecule.

15. Alkenes
The names of the alkenes are composed of
two parts:
𝑆𝑡𝑒𝑚 𝑤𝑜𝑟𝑑 − 𝑒𝑛𝑒
Ethylene C2H4
Propylene C3H6
Butylene C4H8
- - - - - -
CnH2n
more than one structure is possible
for alkenes with four or more
carbon atom
For example,
an alkene with four carbon atoms has
3 possible structures.
CH2=CHCH2CH3 (1-butene)
CH3CH=CHCH3 (2-butene)
[cis (on) and trans (across)]

17. Alkynes
The names of the alkynes are composed of
two parts:
𝑆𝑡𝑒𝑚 𝑤𝑜𝑟𝑑 − 𝑦𝑛𝑒
Ethyne C2H2
Propyne C3H4
Butyne C4H6
- - - - - -
CnH2n-2
CH3C≡CCH3
C4H6

18. Cyclic Hydrocarbons
In a cyclic hydrocarbon, the ends of a hydrocarbon chain are connected to form a ring of
covalently bonded carbon atoms.
The names of the Cyclic Hydrocarbons
are composed of two parts:
𝑐𝑦𝑐𝑙𝑜 − 𝑎𝑙𝑘𝑎𝑛𝑒/alkene/alkyne

20. Functional Groups
The names of the alcohol are composed of
two parts:
𝑆𝑡𝑒𝑚 𝑤𝑜𝑟𝑑 , 𝑟𝑒𝑝𝑙𝑎𝑐𝑒 𝑒 𝑤𝑖𝑡ℎ ′ − 𝑜𝑙′
Ethanol, CH3CH2OH
Ethyl Alchohol, CH3CH2OH
Methanol, CH3OH
Methyl Alchohol, CH3OH
one of the H atoms of ethane is replaced
by an group

21. The presence of functional groups also increases the possibility of isomers.
one propane molecule, C3H8
CH3CH2CH2OH

22. -COOH
-CO2H
Carboxyl group
The hydrogen attached to one of the O atoms in
a carboxyl group is ionizable or acidic.
methanoic acid, HCOOH, Formic acid
ethanoic acid, CH3COOH, Acetic acid
Naming:
Stem name -oic
a halogen atom (F, Cl, Br, I) substituting for one or more H atoms. the halogens names,
fluoro-, chloro-, bromo-, and iodo- would be added : chloroalkane …. CH3CHClCH2CH3