Chemical nomenclature is the system used to name chemical compounds. It allows chemists to communicate effectively. The name of a compound provides information about its structure. There are currently 114 known elements, some of which are gases while most are solids. In the early 1800s, Berzelius established the modern system of using the first letter of the element's name as its symbol. Chemical formulas represent the elements in a compound along with subscript numbers indicating mole ratios. Empirical formulas provide the simplest whole number ratio of atoms in a compound, while molecular formulas give the exact number of atoms in a molecule.

1. CHEMICAL
NOMENCLATURE

2. What’s in the name?
Chemical nomenclature is the term
given to the naming of compounds. It is
used to identify a chemical species by
means of written or spoken words. It is
a useful means for communication
among chemists. The name of the
compound contains within itself an
implied relationship to the structure of
the compound.

3. Lesson 1. Chemical Symbol
There are 114 known elements at present.
 Among the 114 elements, 11 are known to
 be gases. Some of these are oxygen, hydrogen,
nitrogen, chlorine, and helium. Elements
 like neon, argon, krypton,xenon,radon, and
fluorine are very rare and are not found in large
 quantities in nature. All the rest are solids.

4.  Before the year 1814, the chemical symbols
were expressed this way:
Element
Iron
Copper
Gold
Symbol
♂
♀
Ο

5. Then Jon Jacob Berzelius (17791848), a Swedish chemist, started to use
chemical symbols. He used the initial letter
of the element’s Latin or common name in
its capitalized form as its chemical symbols
as follows:
C = carbon
O = oxygen
I = iodine

6. This practice is still
followed today. If the two
elements start with the same
letter, two letters are used as in
the following:
Ca = calcium
Co = cobalt

8. What do you think is the
symbol for each of the
following elements?
a. hydrogen
b. helium
c. boron
d. barium

10. 
1. What is the correct symbol for cuprum?
a. C
b. Cu

c. Cp
d. Cr
2. Which of the following does NOT belong to the group?
a. Argentum
c. Calcium
b. Aurum

d. Kalium
3. Which of the following elements is a solid?
a. argon
b. carbon

c. helium
d. hydrogen
4. What is the English name of stibium?
a. Antimony
b. arsenic

c. lead
d. tin
5. Which of the following does NOT belong to the group?
A. carbon
c. nitrogen
B. hydrogen
d. oxygen

11. Lesson 2. Chemical Formula
 Chemical Formulas:
Chemical formulas such as MgSO4
can be divided into empirical formula,
molecular formula, and structural formula.
The chemical symbols of elements in the
chemical formula represent the elements
present in the compound. The subscript
numbers represent mole proportions of the
preceding elements. If no number is written,
it means the subscript is 1.

12. The Writing of Formulas
 Binary Ionic Compound
(compound composed of metal and a nonmetal)
The metal acts the cation (positively-charged ion)
while the nonmetal forms the anion (negativelycharged ion). The first part of the name of an
inorganic compound is the first part of the formula.

13. Formula Writing of Binary
Ionic compounds
Charge – Crossing Technique

14. Activity
 1. hydrogen chloride (you must know that
this is the common muriatic acid for
cleaning purposes)
 2. calcium fluoride (do you still remember
the anti tartar ingredient of your
toothpaste?)
 3. sodium oxide (the substance behind the
cleansing principle of your laundry
detergent)

15.  1. HCl
 2. CaF2
 3. Na2O

16. The Naming of
Compounds:
Nomenclature

17. Identifying a Compound as
Ionic or Molecular
Metals combined with
nonmetals will produce
compounds that are ionic.
Nonmetals combined with
nonmetals will produce
compounds that are
molecular.

18. Nomenclature of Binary
Ionic Compounds
A binary compound is
made up of two
different elements.

19. Points to remember about naming
a compound from its formula
1. The order for names in a binary
compound is first the cation, then the
anion.
2. Use the name of cation directly
from the periodic table.
3. The name of the anion will be made
from the root of the element's name
plus the suffix "-ide."

20. Example: Write the name of
this formula: H2S

22. QUIZ:

23. Nomenclature of Acids and
Bases
 For the purposes of naming
acids and bases, we will
classify these chemicals into
three categories: binary acids,
ternary acids (sometimes
called oxy-acids), and bases.

24. Binary Acids
 Binary acids contain hydrogen
and one other nonmetallic
element. Their names follow the
pattern of "hydroelementic acid"
where element is replaced by the
root of the name of the element.
These acids contain no oxygen.
Here are some examples.

25. Binary acids

26. Binary Acids





HF (aq)
HCl (aq)
HBr (aq)
HI (aq)
HCN (aq)
hydrofluoric acid
hydrochloric acid
hydrobromic acid
hydroiodic acid
hydrocyanic acid
CHM 1010
PGCC
Barbara Gage

27. Oxyacids
 Acids containing oxygen; most do not exist in
the same form without water:
HNO3
HNO2
H2SO4
H2CO3
H3PO4
HC2H3O2 or CH3COOH
CHM 1010
nitric acid
nitrous acid
sulfuric acid
carbonic acid
phosphoric acid
acetic acid
PGCC
Barbara Gage

28. Bases
 Bases are simply named as ionic
compounds containing the hydroxide
ion. Here are some examples.

29. Lesson 3. Empirical and
Molecular Formula
 Empirical (Simplest) formula is a
formula whose subscripts represent the
simplest whole number ratio of atoms in
a molecule or the simplest whole number
ratio of moles of each element in a mole
of the compound. The simplest formula is
usually determined by considering
experimental data, hence the name
"empirical" which means based on
experimentation.

30.  Molecular formula gives the exact
number of atoms of each element per
molecule of the compound or the
absolute number of moles of each
element per mole of the compound. A
molecular formula may be reducible to
a simple formula if all its subscripts are
divisible by a common denominator.

32. To determine the molecular
formula of the compound,
just follow these steps:
 1. Find the mass of the empirical unit.
 2. Figure out how many empirical
units are in a molecular unit.
 3. Write the molecular formula.

33. Example:
 A compound with an
empirical formula of CH
has a molar mass of 78.
What is its molecular
formula?

34.  Answer:
Step #1.
Step #2.
Step #3.
C : 12 x 1 = 12
H : 1 x 1 = 1_
13
78/13 = 6
(CH)6 = C6H6

35.  On the other hand, if the
empirical formula is asked,
simply divide the subscripts of
the molecular formula with the
greatest common factor. The
resulting SIMPLEST WHOLE
NUMBER represents the
subscript in the empirical
formula.

36. Example: What is the
empirical formula of the
compound Na2C2O4?
 Answer: Just divide the subscripts of
the molecular formula by the
greatest common factor.
The resulting empirical formula is NaCO2.

39. molecular mass C12H22O11 = 12(mass of C) +
22(mass of H) + 11(mass of O)
molecular mass C12H22O11 = 12(12.01) +
22(1.008) + 11(16.00)
molecular mass C12H22O11 = = 342.30