NOMENCLATURE I
The first step in learning nomenclature is to learn the names of the individual elements, polyatomic
ions, and the special names. The second step is to take the names, which you have learned and
combine them though a set of rules. To be able to name compounds will require both of these steps.
Many people make the mistake of only doing the first step. This step is straightforward memorization,
so apply flash cards or some other rote memory method on a daily basis. The second step requires
practice, because there are so many possible combinations that it is not possible to make flash cards
for all of them (there are thousands of possibilities).
By learning, each of the new names when presented in class, plus a little review you should be able to
do the first step. While you should concentrate on the new names, you will need to continue looking
over the older names. The best approach is short study sessions, such as five minutes before or after
each class.
The second step requires learning and applying the nomenclature rules for binary and ternary
compounds. This section examines only binary compounds of the nonmetals. These rules also
include the metalloids and a few ternary compounds that only contain nonmetals and/or metalloids.
Later nomenclature sections will look at other compounds. In some cases, other names may be used;
however only those given in this exercise may receive credit in this class.
NOTE: The metalloids may follow the rules discussed for metals.
Special Names:
Some binary compounds, such as water, have special names. For these few compounds, the method
used in the first nomenclature step is sufficient. These names are fixed; there are no other rules to
apply. Along these lines, do not try to name one of these compounds by the rules given below. Thus,
H2O is water, and no other name is correct.
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Binary Compounds:
All other binary compounds follow one rule–their names end in -ide. (There are a few situations
where a ternary compound may have this ending also.) Other rules in addition to this one are
applicable depending on the type and number of atoms present.
If only nonmetals are present then a multiplying prefix may be necessary. (Hydrogen is the exception
to this, there are no prefixes used for hydrogen in binary compounds.) Multiplying prefixes tell how
many of each type of atom is present. The prefixes are:
1
2
3
4
=
=
=
=
monoditritetra-
5
6
7
=
=
=
pentahexahepta-
8
9
10
=
=
=
octanonadeca-
There are other prefixes, but you are only responsible for these. The prefix mono- is seldom present;
the lack of any prefix indicates the fact that there is only one atom present. The only common
compound where mono is used is CO, carbon monoxide.
Since no prefixes are necessary to designate the number of hydrogen atoms present in a compound, it
is not always easy to predict the correct formula. In general, in the absence of other information, the
position of the element on the Periodic Table indicates the number of hydrogen atoms present in a
binary compound. Beginning with the far right of the table (column VIIIA or column 18), and moving
to the left, the number of hydrogens expected are: 0, 1, 2, 3, and 4. Thus:
He
HF
H2O
NH3
CH4
When putting together the name of a compound normally the element to the right, and/or higher on the
periodic table goes last. Exceptions include the Noble Gases (VIIIA), which are never last, and
hydrogen, which is often last. A discussion of the reason for this ordering appears later in the course.
Whichever element goes last in the name goes last in the written formula too. The ending of the
elemental name that is at the end is changed to -ide. For example:
Hydrogen
Nitrogen
Oxygen
Fluorine
Bromine
= Hydride
= Nitride
= Oxide
= Fluoride
= Bromide
Carbon
Phosphorus
Sulfur
Chlorine
Iodine
= Carbide
= Phosphide
= Sulfide
= Chloride
= Iodide
In compounds containing only nonmetals, the name hydride is seldom used. These same names are
also present in binary compounds containing metals.
Again, this change to an -ide suffix is only used for the element appearing last in the formula or name.
Do not change the ending of the other element.
© 2006 Sevagram Enterprises
Binary Acids:
As with many rules there are exceptions, the special names section presents most of these, the others
are certain compounds of hydrogen. In nomenclature, as elsewhere, hydrogen is a common exception.
One reason why hydrogen is an exception for binary compounds is that some of its compounds are
acids. The binary acids (hydrogen plus certain nonmetals) also have two word names. In their names,
binary acids have a hydro- prefix and an -ic acid ending. For example, HCl is hydrochloric acid.
There are only a few binary acids, the following list are the only ones that you will need to know for
this course:
Binary Compound
Hydrogen fluoride
Hydrogen chloride
Hydrogen bromide
Hydrogen iodide
Hydrogen sulfide
Binary Acid
HF
HCl
HBr
HI
H2 S
Hydrofluoric acid
Hydrochloric acid
Hydrobromic acid
Hydroiodic acid
Hydrosulfuric acid
As with other acids, (see later) the formulas have the H in front. Non-acidic hydrogen compounds
have some other element listed first in the formula (except for H2O).
Technically the binary acids are only acids when they dissolve in water. In other situations, they are
ordinary binary compounds (for example, HCl is hydrogen chloride). For this class either name will
be acceptable unless information is given that indicates which name to use. This information may
appear in a problem, or it may be included with the formula. To indicate, in the formula, that one of
the above compounds must be named as an acid the designation (aq) is used (for example, HCl(aq)).
The aq in parentheses is the abbreviation for aqueous solution–a solution where something dissolves
in water. If anything else is included in parentheses after the name (for example, HCl(g)), it should be
named as a binary compound.
© 2006 Sevagram Enterprises
General:
There are some situations where other nomenclature systems are used. One major alternate system is
for many compounds of carbon–this is the naming of organic compounds. Other systems occur for
many binary hydrogen compounds. You will not be responsible for these systems or for any special
names not given in class. If you see another name, which does not seem to follow these rules just use
it, you are not responsible for memorizing it.
The presence or lack of prefixes determines the formulas for other binary compounds. Mono- or no
prefix indicates that only one atom is present, while prefix gives the number of the other atoms
present.
Carbon dioxide
CO2 (di = 2)
Chlorine trifluoride
ClF3 (tri = 3)
Dinitrogen pentaoxide
N2O5 (di = 2 and penta = 5)
Some of these rules extend to ternary compounds. This occurs only when there are no metals or ions
present. You will not need to learn these, however you should be able to recognize such names should
you see one.
Below are some examples of binary compounds. Look over them and make sure you understand why
the names and formulas appear as they do. These are just a few examples of the hundreds of binary
compounds, so do not expect this list to be complete. (Yes, these compounds all exist.)
AsF3 arsenic trifluoride
TeCl4 tellurium tetrachloride
XeO3 xenon trioxide
SiBr4 silicon tetrabromide
PCl5 phosphorus pentachloride
CO
carbon monoxide
PN
phosphorus nitride
CO2 carbon dioxide
IF7
iodine heptafluoride
P4O10 tetraphosphorus decaoxide
CH4 methane
N2O dinitrogen oxide
NO
nitrogen oxide
N2O3 dinitrogen trioxide
NO2 nitrogen dioxide
N2O4 dinitrogen tetraoxide
N2O5 dinitrogen pentaoxide
S2F10 disulfur decafluoride
S7O2 heptasulfur dioxide
I4O9 tetraiodine nonaoxide
HI(g) hydrogen iodide
HF(aq) hydrofluoric acid
Cl2O7 dichlorine heptaoxide
© 2006 Sevagram Enterprises
GeO2
Sb2S3
KrF2
SeF6
BI3
NH3
H 2S
germanium dioxide
diantimony trisulfide
krypton difluoride
selenium hexafluoride
boron triiodide
ammonia
hydrogen sulfide
or hydrosulfuric acid
H2S(g) hydrogen sulfide
H2S(aq) hydrosulfuric acid
P4O8 tetraphosphorus octaoxide
H2O water
As4S10 tetraarsenic decasulfide
HBr(g) hydrogen bromide
P4S9 tetraphosphorus nonasulfide
OF2 oxygen difluoride
O2F2 dioxygen difluoride
SeBr4 selenium tetrabromide
TeO3 tellurium trioxide
XeOF4 xenon oxide tetrafluoride
HF(l) hydrogen fluoride
HCl hydrogen chloride
or hydrochloric acid
PRACTICE SET I-1
Based on nomenclature section number 1
1. Bismuth
______________
1. Sn
________________________
2. Carbon
______________
2. Al
________________________
________
3. CCl4
________________________
4. Nitrogen dioxide _____________
4. PCl5
________________________
5. Hydrogen bromide _____________
5. B2F4
________________________
6. Sulfur
_____________
6. F
________________________
7. Bromine
_____________
7. H2O
________________________
8. Selenium dioxide _____________
8. ICl3
________________________
9. Carbon monoxide _____________
9. H2S(g)
________________________
10. Boron tribromide _____________
10. SeO3
________________________
11. Nitrogen
11. Pb
________________________
3. Diarsenic pentaoxide
_____________
12. Disulfur decafluoride
_______
12. KrF2
________________________
13. Phosphorus trichloride
______
13. BCl3
________________________
14. Sulfur tetrachloride
______
14. TeO2
________________________
15. Boron triiodide
_____________
15. I2O
________________________
16. Helium
_____________
16. CI4
________________________
17. Silicon
_____________
17. Sb4O6
________________________
18. Diiodine trioxide _____________
18. NH3
________________________
19. Hydrosulfuric acid ____________
19. TeF4
________________________
20. Diantimony trioxide
20. I2O4
________________________
© 2006 Sevagram Enterprises
______
PRACTICE SET I-2
Based on nomenclature section number 1
1. Radon
_____________
1. SbF3
________________________
2. Selenium
_____________
2. XeF2
________________________
3. Silicon dioxide
_____________
3. NF3
________________________
4. Carbon tetrabromide_____________
4. HBr(aq)
________________________
5. Iodine chloride
_____________
5. I2O5
________________________
6. Tin
_____________
6. Sb2O5
________________________
7. Iodine
_____________
7. OF2
________________________
8. Arsenic trichloride _____________
8. HCl(g)
________________________
9. Diphosphorus pentaoxide _______
9. GeBr4
________________________
10. Dichlorine oxide _____________
10. TeF6
________________________
11. Argon
11. Bi
________________________
12. ClF
________________________
13. SCl2
________________________
14. SeF4
________________________
_____________
12. Antimony triiodide
13. Carbon dioxide
______
_____________
14. Dibromine trioxide
______
15. Hydroiodic acid
_____________
15. B2O3
________________________
16. Tellurium
_____________
16. CF4
________________________
17. Selenium hexafluoride
_______
17. CS2
________________________
18. Germanium dioxide
_______
18. BrF3
________________________
19. Selenium tetrachloride
_______
19. HF(g)
________________________
20. Dichlorine heptaoxide
_______
20. N2O5
________________________
© 2006 Sevagram Enterprises
PRACTICE SET I-3
Based on nomenclature section number 1
1. Arsenic
_____________
1. I
________________________
2. Oxygen
_____________
2. IF7
________________________
_______
3. SiCl4
________________________
4. Disulfur dibromide _____________
4. Cl2O4
________________________
5. Hydrochloric acid _____________
5. SiC
________________________
6. Hydrogen
_____________
6. SF4
________________________
7. Phosphorus
_____________
7. NO
________________________
3. Antimony trichloride
8. Nitrogen trichloride
_______
8. XeO4
________________________
9. Silicon tetrabromide
_______
9. HI(g)
________________________
10. Tetraiodine nonaoxide
_______
10. S2F4
________________________
11. Chlorine
______________
11. Sb
________________________
12. Xenon
______________
12. SeF4
________________________
14. Hydrofluoric acid ______________
13. TeO3
________________________
14. Dinitrogen difluoride
________
14. B2Br4
________________________
15. Dichlorine dioxide______________
15. As4O6
________________________
16. Germanium
16. XeF4
________________________
______________
17. Sulfur hexafluoride
________
17. PF5
________________________
18. Carbon tetrafluoride
________
18. N2F4
________________________
______________
19. CH4
________________________
20. S2Cl2
________________________
19. Sulfur trioxide
20. Dinitrogen tetraoxide
© 2006 Sevagram Enterprises
________
PRACTICE SET I-4
Based on nomenclature section number 1
________
1. ClO2
________________________
______________
2. AsF3
________________________
3. Tetraphosphorus hexaoxide_________
3. GeCl4
________________________
4. Ditellurium pentaoxide
________
4. H2Se
________________________
5. Iodine pentafluoride
________
5. P4O10
________________________
6. Selenium difluoride
________
6. AsBr3
________________________
1. Antimony tribromide
2. Bromine dioxide
7. Boron
______________
7. SbF5
________________________
8. Krypton
______________
8. BrO2
________________________
9. Al
________________________
10. Diarsenic trioxide ______________
10. N2O3
________________________
11. Bromine chloride
11. XeO3
________________________
12. BF3
________________________
9. Diphosphorus trioxide
12. Neon
________
________
______________
13. Tetrasulfur tetranitride
________
13. Si2Cl6
________________________
14. Tellurium tetrafluoride
________
14. He
________________________
15. Diantimony tetraoxide
________
15. BrO3
________________________
16. Ar
________________________
16. Antimony
______________
17. Silicon tetrafluoride
________
17. O2F2
________________________
18. Chlorine trifluoride
________
18. SeF6
________________________
19. Selenium tetrachloride
________
19. NBr3
________________________
20. Chlorine pentafluoride
________
20. As2S3
________________________
© 2006 Sevagram Enterprises
PRACTICE SET I-5
Based on nomenclature section number 1
1. Antimony pentachloride
1. Br
________________________
2. Tetraphosphorus decasulfide________
2. Rn
________________________
3. Diboron tetrachloride
3. IF3
________________________
4. Aluminum bromide______________
4. SO2
________________________
5. Dinitrogen oxide ______________
5. P4O8
________________________
6. Antimony
6. Kr
________________________
7. Ne
________________________
8. Germanium dichloride____________
8. XeF6
________________________
9. Tribromine octaoxide
_________
9. Sb2S3
________________________
10. Bromine pentafluoride
________
10. BN
________________________
11. Diantimony triselenide
________
11. Xe
________________________
12. Phosphorus tribromide
________
12. Cl
________________________
13. Radon difluoride ______________
13. SeBr2
________________________
14. Carbon diselenide ______________
14. AsF5
________________________
15. Diarsenic tetraiodide
15. P2Cl4
________________________
______________
16. Ge
________________________
17. Hydrogen telluride______________
17. Te
________________________
18. Boron phosphide ______________
18. SeBr4
________________________
19. Iodine fluoride
19. S2I2
________________________
20. Ge3Cl8
________________________
________
______________
7. Tetraboron tetrachloride
16. Lead
________
________
________
______________
20. Tetraphosphorus nonaoxide_______
© 2006 Sevagram Enterprises