The document discusses several laws of chemical changes and principles of naming chemical compounds. It describes the law of conservation of mass, law of definite proportions, and law of multiple proportions. It also discusses Dalton's atomic theory and how it can explain these laws. The document provides rules for naming binary, ternary, molecular, and acidic compounds based on their composition and oxidation states. Examples of naming ionic compounds, acids, and writing chemical formulas from compound names are also presented.

2. Laws of
chemical
changes

3. Law of Conservation of Mass: In a
chemical reaction, no change in mass takes
place. The total mass of the products is equal
to the total mass of the reactant.

4. Antoine Lavoisier, a
brilliant French chemist,
formulated this law by
describing one of his
experiments involving
mercuric oxide. He
placed a small amount
of mercuric oxide, a red
solid, inside a retort and
sealed the vessel tightly.

5. He weighed the system, and then subjected it
to high temperature. During the heating, the
red solid turned into a silvery liquid. This
observation indicated that a chemical reaction
took place. After which, the setup was cooled
and then weighed. The weight of the system
was found to be the same as before heating.

6. Law of Definite
Proportion: A
compound always
contains the same
constituent elements
in a fixed or definite
proportion by mass.

7. If water samples
coming from different
sources are analyzed,
all the samples will
contain the
same ratio by mass of
hydrogen to oxygen.

8. a. Describe an experiment wherein different
amounts of magnesium powder are heated
in air.
b. Magnesium burns brightly in air and reacts
with oxygen. During the reaction, the gray
powder turns into a white substance. The
reaction causes the weight of the solid to
increase.
c. The following data were collected:

10. d. Ask them to complete the third column by
applying the Law of Conservation of Mass.
e. Ask them to fill up the fourth column by
dividing the mass of oxygen (third column)
by the mass of the magnesium (first
column).

12. Law of Multiple
Proportions: If two
elements can combine
to form more than
one compound, the
masses of one element
that will combine with a
fixed mass of the other
element are in a ratio of
small whole numbers.

13. Example: A carbon molecule which reacts
with oxygen to form carbon monoxide and
carbon dioxide.
a. In carbon monoxide, 1.00 g carbon
combines with 1.33 g oxygen; whereas, in
carbon dioxide, 1.00 g carbon combines with
2.66 g oxygen.
b. It can be seen that the ratio is 1:2.

14. Dalton’s Atomic Theory,
proposed by John Dalton,
can be used to explain
the laws of chemical
change. This theory is
based on the following set
of postulates:

15. 1. Elements
are made up
of very small
particles
known as
atoms.

16. 2. All the atoms of an element are
identical in mass and size, and are
different from the atoms of another
element. Dalton used the different
shapes or figures to represent
different elements, as follows:

17. 3. Compounds are composed of
atoms of more than one element,
combined in definite ratios with
whole number values.

18. 4. During a chemical reaction,
atoms combine, separate, or
rearrange. No atoms are created
and no atoms disappear.

19. Which postulate could provide
an explanation for the:
a. Law of Conservation of Mass?
b. Law of Definite Proportion?

20. During the time of Dalton, the
atom was believed to be the
smallest particle comprising
substances. However, before the
end of the 19th century,
experiments
provided proof of the existence of
smaller particles within the atom.

21. Subatomic
particles

24. The above numbers are defined
by the following equations:
a. Atomic number = number of
protons = number of electrons in
a neutral atom
b. Mass number = number of
protons + number of neutrons

27. ISOTOPES – atoms of an
element having the same atomic
number but different mass
number. The existence of
isotopes was shown by mass
spectroscopy experiments,
wherein elements were found to
be composed of several types of
atoms, each with different
masses.

28. a. The atomic number
identifies an element.
The atoms of isotopes
of an element have
the same number of
protons and electrons.
b. The atoms of
isotopes of an element
differ in the number of
neutrons.

29. Complete the following table containing
information about the isotopes of hydrogen:

30. The common hydrogen atom is protium, while
deuterium is found in heavy water.

31. Recall the difference between
the following particles:
a. Atom
b. Molecule
c. Ion

32. Complete the following concept map showing
the relationship of these particles:

33. Complete the following concept map
showing the relationship of these particles:

34. Each element has a characteristic atom.
a. Dalton differentiated the elements and their
atoms through drawings.
b. However, in present day, elements are
differentiated and represented through
symbols.
i. Many symbols are abbreviations derived from
the name of the element.
ii. Some symbols are derived from their Latin
names.

35. What are examples of
elements and their names and
symbol?

36. The difference between an ion
and an atom is the presence of
charges.
The simple ions are derived
from atoms through the gain or
loss of an electron.

37. Complete the following concept map
showing the relationship of these particles:

39. Ions can be made up
of only one atom
(monoatomic) or
more than one type
of atom
(polyatomic).

41. Monoatomic ions are named based on the
element.
a. For cations, the name of the element is
unchanged. If an element can form two ions of
different charges, the name, which is usually
derived from its Latin name, is modified by
the suffix –ic for the ion with the higher charge,
and –ous for that with the lower charge.
b. For anions, the name of the element is
modified by the suffix –ide.

42. Name the following cations:
a. Zn2+
b. Mg2+
c. K+
d. Fe2+
e. Fe3+

43. Name the following cations:
a. Zn2+ – zinc ion
b. Mg2+ – magnesium ion
c. K+ – potassium ion
d. Fe2+ – ferrous ion or iron (II) ion
e. Fe3+ – ferric ion or iron(III) ion

44. Name the following anions:
a. Br
b. S2-
c. O2-
d. I-

45. Name the following anions:
a. Br- – bromide ion
b. S2- – sulfide ion
c. O2- – oxide ion
d. I- – iodide

46. Several anions are polyatomic and
are named based on the atomic
constituents and the suffix – ide.
The most common examples are:
a. OH- – hydroxide ion
b. CN- – cyanide ion

47. A number of polyatomic anions
containing oxygen atoms are
named based on the root word of
the central (or non-oxygen) atom
and the suffix –ate for the one with
more oxygen atoms and –ite for the
one with less oxygen atom.

48. a. NO3 - – nitrate ion
b. NO2 - – nitrite ion
c. SO3 2- – sulfite ion
d. SO4 2- – sulfate ion
e. PO4 3- – phosphate ion
Some anions have common names ending with the suffix –ate.
a. C2H3O2- – acetate ion b. C2O42- – oxalate ion

49. The composition of a molecule or an ion
can be represented by a chemical
formula. The formula consists of the
symbols of the atoms making up the
molecule. If there is more than one atom
present, a numerical subscript is used.

50. Examples are the following:
a. O2 – oxygen gas
b. H2O – water
c. NaOH – sodium hydroxide (liquid Sosa)
d. HCl – hydrochloric acid (muriatic acid)

51. There are two types of
chemical formulas:

52. Molecular formula – gives the
composition of the molecule,
in terms of the actual
number of atoms present.

53. Examples are the
following:
i. C6H12O6
ii. K3PO4
iii. Na2C2O4

54. Empirical formula – gives the
composition of the molecule, in
terms of the smallest ratio of the
number of atoms present.
Examples are the following:
i. CH2O
ii. NaCO2

55. The naming of compounds
follows a set of rules.
the rule of naming of binary
compounds. Binary compounds
– made up of two elements.

56. a. Covalent compounds
(NONMETAL + NONMETAL)–
for the first element, start with
the element name. For the
second element, start with the
–ide name.

57. a. Covalent compounds
(NONMETAL +
NONMETAL)– cont.
Use prefixes to show how
many atoms of each type
there are.

58. Example:
N2O3

59. N2O3
Nitrogen oxide
Using
Prefixes
1 mono-
2 di-
3 tri-
4 tetra-
5 penta-
6 hexa-
7 hepta-
8 octa-
9 nona-
10 deca-

60. N2O3
Dinitrogen trioxide
Using
Prefixes
1 mono-
2 di-
3 tri-
4 tetra-
5 penta-
6 hexa-
7 hepta-
8 octa-
9 nona-
10 deca-

61. How about
P4S10

62. How about
P4S10
Tetraphosphorous
decasulfide

63. a. Covalent compounds
(NONMETAL +
NONMETAL)– cont.
DO NOT USE MONO- in the
first element

64. CF4
Monocarbon
tetrafluoride

65. CF4
Carbon
tetrafluoride

66. a. Covalent compounds
(NONMETAL +
NONMETAL)– cont.
If you have “ao” or “oo”, turn
it into “o”

67. P4O6
Tetraphosphorous
hexaoxide
Example:

68. P4O6
Tetraphosphorous
hexoxide
Example:

69. CO
Carbon monooxide
Example:

70. CO
Carbon
monoxide
Example:

71. b. Ionic compounds (METAL +
NONMETAL)– made up of a
cation and an anion. They are
named by giving the name of the
cation first, followed by the
name of the anion.

72. Oxidation states

73. Name the following
compounds:
i. NaI
ii. MgCl2
iii. FeS
iv. K2O

74. Name the following
compounds:
i. NaI – Sodium iodide
ii. MgCl2 – Magnesium chloride
iii. FeS – Iron (II) sulfide
iv. K2O – Potassium oxide

75. Roman
Numerals
1 I
2 II
3 III
4 IV
5 V
6 VI
7 VII
8 VIII
9 IX
10 X
FeCl3
Fe 2+ Iron (II)
Fe 3+ Iron (III)

76. Roman
Numerals
1 I
2 II
3 III
4 IV
5 V
6 VI
7 VII
8 VIII
9 IX
10 X
Fe 2+? Fe 3+?
FeCl3
Cl-
Cl-
Cl-
3-
Fe
Fe
Fe
3+

77. Roman
Numerals
1 I
2 II
3 III
4 IV
5 V
6 VI
7 VII
8 VIII
9 IX
10 X
FeCl3
Iron (III) Chloride

78. Try this:
CrBr2

79. Try this:
CrBr2
Chromium (II) bromide

80. Try this:
Au2S

81. Roman
Numerals
1 I
2 II
3 III
4 IV
5 V
6 VI
7 VII
8 VIII
9 IX
10 X
Au2S
S2-
____
2-
Au
Au
2+

82. Gold (I) sulfide
Try this:
Au2S
This means that the roman numeral does not stand
for the amount of atoms but the value of the charges

83. Try this:
Co3N2

84. Roman
Numerals
1 I
2 II
3 III
4 IV
5 V
6 VI
7 VII
8 VIII
9 IX
10 X
Co3N2
N3-
N3-
____
6-
Co
Co
Co
6+

85. Cobalt (II) nitride
Try this:
Co3N2
This means that the roman numeral does not stand
for the amount of atoms but the value of the charges

86. Oxidation states

87. Note: Zinc, Cadmium, and Silver does not need
Roman Numerals because there is only one
possible ion

88. b. Molecular compounds – made up
of two non-metals. They are named
by giving the name of the first
nonmetal and then that of the
second nonmetal modified by the
ending - ide. Molecular compounds
are usually gases.

89. Name the following
compounds:
i. HCl
ii. CO2
iii. SO3

90. Name the following
compounds:
i. HCl – hydrogen chloride
ii. CO2 – carbon dioxide
iii. SO3 – sulfur trioxide

91. Now let’s discuss the rules for naming
ternary compounds – made up of three
elements. The naming of ternary
compounds follows the same rule as
that of the binary ionic compound: the
name of the cation is given first,
followed by the name of the anion.

92. Name the following
compounds:
i. NaNO3
ii. BaCrO4
iii. K2SO4

93. Name the following
compounds:
i. NaNO3 – sodium nitrate
ii. BaCrO4 – barium chromate
iii. K2SO4 – potassium sulfate

94. Naming of Acids
Acids – yield hydrogen
ions in aqueous
solutions.

95. a. Binary acids – composed of
hydrogen and another element,
usually a nonmetal. The first
part of the name starts with the
prefix hydro- followed by the
name of the element, modified
by the ending –ic.

96. The second part
consists of the word
‘acid’. Name = hydro-
(root name of element) -
ic + acid

97. Name the following binary
acids:
i. HCl
ii. H2S
iii. HI

98. Name the following binary
acids:
i. HCl – hydrochloric acid
ii. H2S – hydrosulfuric acid
iii. HI – hydroiodic acid

99. b. Ternary acids – made up
of hydrogen and an anion,
usually containing oxygen.
The first part of the name
consists of the root word of
the name of the element,
modified by the ending –ic.

100. The second part consists of the
word ‘acid’. If there is another
acid with the same atoms, the
suffix –ous is used to denote
the one with less number of
atoms. Name = (root name of
element) -ic (or –ous) + acid

101. Name the following ternary acids:
i. HNO3
ii. HNO2
iii. H2SO4
iv. H2SO3
v. H3PO4

102. Name the following ternary acids:
i. HNO3 – nitric acid
ii. HNO2 – nitrous acid
iii. H2SO4 – sulfuric acid
iv. H2SO3 – sulfurous acid
v. H3PO4 – phosphoric acid

103. Now you have become familiar
with the naming of compounds,
it would be easy to write the
formula of the compound.

104. In writing the formula, the
total positive charges of the
cations should be equal to
the total of the negative
charges of the anion. The net
charge should be zero.

105. Write the formula of the following
compounds, given the name of the
compound:
i. Silver nitrate
ii. Potassium iodide
iii. Nitrogen dioxide
iv. Barium chloride
v. Hydrobromic acid

106. Write the formula of the following
compounds, given the name of the
compound:
i. Silver nitrate – AgNO3
ii. Potassium iodide – KI
iii. Nitrogen dioxide – NO2
iv. Barium chloride – BaCl2
v. Hydrobromic acid – HBr