CHEMISTRY SS 1
E – LEARNING NOTES
FIRST TERM SCHEME OF WORK
WEEK TOPICS/CONTENTS
1. INTRODUCTION TO CHEMISTRY
Career prospect in chemistry/application of chemistry
Scientific approach/method of discoveries
Effect of chemicals e.g drug abuse, poisoning, pollution, corrosion
Familiarization of laboratory apparatus
Drawing of laboratory apparatus
2. NATURE OF MATTER
Definition of matter
State of matter and changes in state of matter
Sublimation, evaporation etc
Properties of matter
Definition of physical and chemical properties
Difference between physical and chemical properties
3. ELEMENTS AND THEIR SYMBOLS
Definition of elements and the symbol of the first 30 elements
Classification of elements into the three state of matter e.g. sodium is
solid, neon is gas, and mercury is liquid
4. IUPAC NUMENCLATURE OF INORGANIC COMPOUND
Rules of IUPAC nomenclature
Concept of oxidation number and their uses
Conventional system of naming compound
5. STANDARD SEPERATION TECHNIQUE
Classification of substances
Filtration, evaporation, decantation, floatation, frostation
6. STANDARD SEPERATION TECHNIQUE condt
Crystallization, and fractional crystallization
Distillation and fractional distillation
Precipitation, magnetism, chromatography, centrifugation,
sublimation
Pure and impure substances
7. PARTICULATE NATURE OF MATTER
Concept of atoms, molecules and ions
Dalton’s atomic theory and its modification
8. CONSTITUENT OF ATOMS
Proton, electron and neutron
Arrangement of element in an atom
Atomic number, atomic mass, isotopes and calculation of relative
abundance of isotopes
9. STRUCTURE OF THE ATOM
Orbital and electrons structure of the atom
Rules and principles of filling the electrons
10. ELECRONIC CONFIGURATION OF ATOMS
Using energy levels and sub energy levels
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Formation of ions and valency
Writing formulas of compound using valency
11. REVISION
12. EXAMINATION
INTRODUCTION TO CHEMISTRY
Objectives:
At the end of this topic, you should be able to:
1. Meaning of chemistry
2. Career prospects tied to chemistry
3. Application (i) Hospital (ii) Military (iii) Teaching (iv) Chemical and petrochemical industries.
4. Adverse effects of chemicals, drug abuse, poisoning, Corrosion and pollution.
5. Scientific methods.
6. list common laboratory apparatus/equipment and state their uses
MEANING OF CHEMISTRY
Chemistry is the study of matter: its structure, composition, properties, and the changes it undergoes.
Chemistry is one of the three main branches of pure science, the other two being physics and biology.
Chemistry which probes into the principles governing the changes that matter undergoes also deals with
the composition, properties and uses of matter. Some of the chemical changes which matter undergoes
include lighting a match, cooking, burning fire wood, making palm wine, rusting of nails, rotting of
leaves. Chemical changes are otherwise known as chemical reactions.
The knowledge of chemistry helps us to subject some matter to chemical processes thereby producing
some materials for our everyday use. Such materials include soaps, detergents, hair cream, perfumes,
oil, margarine and plastics among others.
There are three main branches of chemistry: inorganic, organic and physical chemistry.
Career prospects tied to chemistry
Career prospects tied to chemistry simply mean the job opportunities that are available for the students
with knowledge of chemistry. Such students can be employed with private and public sectors which
include: Teaching service, health service, food processing, petroleum and petrochemical industries,
manufacturing industry, extractive industry, Agriculture and Forestry.
(i) Teaching services: Concern those who teach in primary, secondary schools, colleges of
education and universities and even the laboratory assistants in schools and universities.
(ii) Health service: Involves pharmacists, biochemists, chemists, nutritionists, dieticians,
doctors, nurses, medical assistants, laboratory assistants and dispensers.
(iii) Food processing: Food processing involves food technologists and research chemists.
(iv) Petroleum and petrochemical industries –Involves application of the following people;
research chemists, chemical engineers and laboratory assistants.
(v) Extractive industry- Involves chemists, mining engineers and geologists.
(vi) Manufacturing Industry: This involves research chemists and chemical engineers in the
wide variety of manufacturing industries such as iron and steel works and cement factories.
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(vii) Agriculture-Involves agricultural scientists, chemists, biochemists, and physiologists who
engaged in research to improve the quality and yield of crops and livestock, and to advise
farmers.
(viii) Forestry: Scientists engaged in research to preserve and improve forests and forestry
products.
APPLICATION/ USES OF CHEMISTRY
The knowledge of chemistry can be applied in the following areas; namely
1. Hospital: The knowledge of chemistry makes it possible for people to involve in chemical
research and technology which lead to production of medicine that we use today.
2. Military: The duty of the military is defence, to defend the territorial integrity of a nation or
state. Military cannot effectively do this without ammunition. Chemistry contributes to the
discovery and description of the theoretical bases for the behaviour of chemical substances such
as explosives used by the military. The gun powder used in the earliest guns was made by
mixing sulphur, charcoal, and potassium trioxonitrates (v), compounded by early chemists. The
manufacture of smokeless powder was based upon gun cotton, which is made from cotton fibers
soaked in a strong mixture of HNO3 and H2SO4.
3. Teaching- chemistry teachers and lecturers in secondary schools, polytechnics, colleges of
education and universities.
4. Chemical and petrochemical industries: Application chemists, research chemists, chemical
engineers, and laboratory assistants.
5. Space science: chemistry is not out in space exploration. In our efforts to gain more knowledge
of the other planets and outer space around us, special rockets called ‘space rocket’ are sent
into space. The first rocket was sent into space on October 4, 1957, by Russia. In July 1969,
Apollo II astronauts Neil Armstrong and Edwin Aldrin landed on the moon. These are made
possible by science and technology.
6. Agriculture: Agricultural scientists, chemists, biochemists, and physiologists engaged in
research to improve the quality and yield of crops and livestock, and to advise farmers.
ADVERSE EFFECTS OF CHEMICALS
The adverse effects of existence of chemistry
The existence of chemistry brought about the existence of chemicals. The adverse effects of
chemicals include: drug abuse, poisoning, corrosion and pollution.
(a) Drug Abuse: simply involves wrong usage of drugs. Some of these drugs include heroin,
cocaine and morphine which are used as addictive. Unscrupulous people produce and sell them
at huge profits. Drug addiction is a major problem in our society, especially among young
people. Many countries have imposed strict laws to control pollution and drug abuse. However,
the most effective control measure is education. We must use what we learnt to improve our
life and to control these abuses.
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(b) Poisoning: This is where chemicals are used to poison the food we eat. This happens when the
chemicals used as addictive probably as preservative are added more than required or expired
in the food stuff where it was added, then instead of the food stuff bringing health to our body,
it turns to poison.
(c) Corrosion: Corrosion of iron can also be called rusting and requires the presence of water and
oxygen. Rusting can also be regarded as the slow deterioration of iron to iron (iii) oxide. This
iron (iii) oxide is permeable to both air and water and cannot protect the iron from further
corrosion of iron.
This rusting can be prevented by four methods.
(i) Application of protective coating.
(ii) Application of sacrificial metal.
(iii) Alloying.
(iv) Cathodic protection.
(d) Pollution: Chemical industries through the action of production pollute our environment as the
smoke enters into the air, and dirt of different kinds enter into the water thereby polluting the
entire environment. Specifically chemical wastes from factories and oil refineries and
radioactive wastes from nuclear plants pollute our environment. Oil spillage, exhaust from
motor vehicles, pesticides, fertilizers and acid rain have made our environment unclean and
endangered plant and animal life. Human health is also being threatened by environmental
pollution. Presently, chemists are trying to come up with a fuel that will reduce the air pollution
problem. They are also modifying chemical processes to recycle chemical wastes or change
them to harmless products which can be safely discharged into the surrounding.
SCIENTIFIC METHOD
This is the method the scientist used to produce different materials that exists because of chemistry.
In the light of this, the scientists use their senses to observe what is happening around them. From
a given set of observations, they see a certain pattern. This often leads to a problem which they try
to solve. They put forward a reasonable explanation or hypothesis and carry out appropriate
experiments to test it. Then, they carefully record their observations and the results of their
experiments.
If the experiments support the hypothesis, they carry out further investigations. They discuss the
hypothesis and results with other scientists in the field so that the hypothesis can be further tested.
When a hypothesis has been tested and found to be correct within the limits of available evidence.
It becomes a theory. A scientific law or principle is established only after the theory has been
extensively tested and proven true without any exception. If the experiments give negative results,
then the scientist goes back to his hypothesis and either modifies it or puts forward a new
hypothesis. This way of studying a problem is known as the scientific method. It is the very
foundation of all scientific discoveries.
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COMMON LABORATORY APPARATUS AND THEIR USES
BEAKERS
Beakers are useful as a reaction container or to hold liquid or solid
samples.
They are also used to catch liquids from titrations and filtrates from
filtering operations.
CONICAL FLASK OR ERLENMEYER FLASKS
Conical Flasks are useful to contain reactions or to hold liquid samples.
They are also useful to catch filtrates.
TEST TUBES
Test Tubes are for holding small samples or for containing reaction mixture
TEST TUBE HOLDERS
Test tube holders are for holding test tubes when tubes should not be
touched
BURRETTES
Burrettes are for addition of a precise volume of liquid.
Note: The volume of liquid added can be determined to
the nearest 0.01 mL with practice.
PIPETTES
Pipette are used to dispense small quantities of liquids.
DROPPERS
Droppers are for addition of liquids drop by drop
MEASURING CYLINDERS
Measuring cylinder also known as graduated Cylinders are for measurement
of an amount of liquid.
Note: The volume of liquid can be estimated to the nearest 0.1 mL with practice.
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VOLUMETRIC FLASKS
Volumetric Flasks are used to measure precise volumes of liquid
or to make precise dilutions.
GLASS FUNNELS
Glass Funnels are for funneling liquids from one container to another or for
filtering when equipped with filter paper.
BUNSEN BURNERS
Bunsen Burners are sources of heat.
HOT PLATES
Hot Plates can also be used as sources of heat when an open flame is not
desirable.
RETORD STAND WITH CLAMP
Retord stand with clamp are for holding pieces of glassware in place.
TONGS
Tongs are similar in function to forceps but are useful for larger items.
WASH BOTTLES
Wash bottles are used for dispensing small quantities of distilled
water.
Dilution mark
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WATCH GLASSES
Watch glasses are for holding small samples or for covering beakers
or evaporating dishes.
WIRE GAUZE
Wire Gauze on a tripod stand or ring supports beakers to be heated by
bunsen burners
CLAY TRIANGLES
Clay Triangles are placed on a ring attached to a ring stand as a
support for a funnel, crucible, or evaporating dish.
SPATULA
Spatula is used to mix, spread, lift substances
Its used for scaping materials out of beakers etc
LABORATORY EQUIPMENT
BALANCES
Balances are used to determine the mass of a reagent or
object.
SPECTROPHOTOMETERS
Spectrophotometers are used to measure the absorbance or
transmittance of a liquid sample.
FUME CUPBOARD
Fume cupboards are used to ventilate noxious or harmful
gases.
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COMMON LABORATORY TECHNIQUES
READING MENISCUS
In all volumetric glassware (pipette, burette, volumetric flasks, graduated cylinder, etc.), it is
necessary to read the level of a liquid. A liquid in a small-diameter container will form a meniscus or
curve at the surface of the liquid. Usually this meniscus curves
downward to a minimum at the center.
To read the level of the liquid properly, the eye should be at the
same level as the bottom of the meniscus. Sometimes a white
card or a white card will help a person to see the meniscus clearly.
For volumetric flasks and transfer pipette, the volume
of the glassware is exact when the bottom of the
meniscus is even with the etched line.
In a graduated cylinder or a burette, the volume is read
from the graduations etched on the glass.
NOTE: To read the volume correctly, visualize the distance
between the tenths of milliliter marks as divided into ten equal
amounts. The volume is then found by reading the number of
tenths of cubic centimeters or milliliters and estimating
hundredths of cubic centimeters or milliliters.
CARE OF REAGENT
The reagents used by all of the students can be contaminated by one careless student. Never put
anything back into the reagent bottle. A certain amount of liquid can be obtained in several ways:
1. Pour from the reagent bottle into a beaker and draw up the liquid into a pipette from the beaker.
2. Pour from the beaker into a graduated cylinder to within 0.1 ml of the desired amount, adding the
last drop with an eyedropper filled from a beaker.
3. Only use appropriately labeled spatulas for each reagent bottle. Pour the solid into a beaker, onto
weighing paper, or into a weigh boat. Never pour excess back into the bottle.
4. Reagents are to remain on the plastic on the center bench. This will
prevent spills and accidents from occurring at your work area
save time for everyone because all of the chemicals will be relatively easy to find in a central
location, and
Make clean-up easier if a spill does occur. When you are finished using a chemical, replace
the lid! A mix-up of lids could also contaminate an expensive chemical.
LIGHTING THE BUNSEN BURNER
Lighting the Bunsen burner - Make sure the rubber tubing is connected to the Bunsen
burner and the gas jet. Turn the gas valve until it is parallel to the gas jet. You should be
able to hear the gas flow. Use a flint striker to cause a spark and ignite the gas. Adjusting
the Bunsen burner - First, adjust the height of the flame using the gas valve at the bottom
of the burner. For a clean burning flame, more air is required than is available from the
gas exhaust. The air vents can be adjusted to produce an inner blue cone in the flame with
no yellow tip. Too little air produces a sooty, orange-yellow tipped flame that is quite
noisy. Too much air supply may cause the flame to separate from the burner and even
blow itself out. The ideal working flame is bluish-green with a light blue cone and it
burns quietly.
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NATURE OF MATTER AND SEPARATION TECHNIQUES
OBJECTIVES
At the end of this topic, you should be able to:
1. Define matter
2. Mention the various state of matter
3. Explain change of state
4. Distinguish between physical change and chemical change
5. Define element, compound, and mixture
6. State the difference between element compound and mixture
MATTER
Matter may be defined as anything that has mass and occupies space. Mass is a measure of quantity of
matter.
The mass of a body which is determined by means of an analytical balance is invariable, while the
weight of a body is not. Weight is the gravitational force of attraction exerted by the earth on a body.
The weight of a given body varies with the distance of that body from the centre of the earth. The weight
of a body is directly proportional to its mass as well as the earth's gravitational attraction.
STATE OF MATTER
Matter exists in three physical states which are:
1. Solid
2. Liquid and
3. Gas
NOTE: there is now a fourth and fifth state known as PLASMA and LIQUID CRYSTAL
PROPERTIES OF SOLID:
i. They are tightly packed or held together
ii. They have definite shape and definite volume
iii. They cannot move from one place to another, however they vibrate within a fixed position
iv. They have the lowest kinetic energy
v. They cannot be compressed
PROPERTIES OF LIQUID:
i. They are loosely packed or held together
ii. They have no definite shape, however they assume the shape of their container but definite
volume
iii. They can move from one place to another, however, their movement is limited
iv. Their kinetic energy is higher than that of solid but lower to that of gas
v. They cannot be compressed
PROPERTIES OF GAS:
i. They are more loosely packed or held together
ii. They have no definite shape and no definite volume
iii. They can move from one place to another without limitation
iv. They have the highest kinetic energy
v. They can be compressed, because they fill their container
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CHANGE OF STATE
The three states of matter of matter are interchangeable, that is, a particular state of matter can be
converted or changed to another state. For example, when a matter in its solid-state changes to liquid,
it is said to have undergone melting. The diagram below illustrates the change of state.
PROPERTIES OF MATTER
There are two properties of matter which are:
1. Physical properties
2. Chemical properties
Physical properties are the properties associated with physical changes. These properties are
the intrinsic properties of matter because they can be observed without causing any change in
the chemical composition of the matter. Examples include:
i. Density
ii. Colour, taste and smell of a substance
iii. Physical state
iv. Melting point
v. Boiling point
vi. Hardness and
vii. Electrical conductivity
Chemical properties are the properties associated with chemical changes. These properties are
the extrinsic properties of matter since they are the changes that matter undergo. Examples
include:
i. Corrosion
ii. Burning etc.
PHYSICAL CHANGES
A physical change is one which is easily reversed and produces no new substances. Examples incude:
i. The dissolution of common salt in water is a physical change because no new substance is
formed and the salt can be recovered by evaporating the solution to dryness.
ii. Changes in state: such as
the melting of a solid, e.g., ice, candle wax etc.
the liquefaction of gases to liquids
the freezing and vaporization of a liquid
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iii. Physical means: such as filtration, evaporation, distillation, sublimation and crystallization may
be used to separate the components of a mixture, but a substance that was not present in the
original mixture is never produced by these means.
iv. Magnetization and demagnetization of iron rods.
CHEMICAL CHANGES
Chemical change is a change which is not easily reversed and in which new substances are formed.
Physical means cannot be used to separate the components. Examples include:
i. Burning of substances e.g., wood
ii. Addition of water to calcium oxide (quick lime)
iii. Burning of magnesium ribbon in Bunsen flame. It burns with a bright white flame to form white
ashes of magnesium oxide.
iv. The rusting of iron in moist air
v. Reaction of metals and calcium trioxocarbonate (IV) with dilute acids
vi. Reaction of some metals with water to produce the corresponding alkalis and hydrogen gas.
DIFFERENCES BETWEEN PHYSICAL AND CHEMICAL CHANGES
PHYSICAL CHANGES CHEMICAL CHANGES
1. It is easily reversible it is not easily reversible
2. It produces no new substances New substances are produced
3. There is no change in the mass of substance
involved
There is change in the mass of substance involved
4. It does not involve any great heat changes except
latent heat changes which occur during change of
state e.g., heat of dissolution, latent heat of fusion
and vaporisation
A considerable amount of heat change is involved,
e.g., explosion of coal gas or hydrogen with air.
CLASSIFICATION OF MATTER
There are three classifications of matter, they include:
1. Elements
2. Compound and
3. Mixture
ELEMENTS
An element is a substance which cannot be split into simpler units by ordinary chemical process.
Elements constitute the building block of all other substance.
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There are 118 known elements. Ninety of them, occur naturally, while the rest are made artificially in
the laboratory. Elements are arranged according to their atomic number.
CLASSIFICATIONS OF ELEMENT
Elements are classified into
i. Metals
ii. Metalloids and
iii. Non-metals.
NOTE: The metalloid are those that share the properties of both the metals and non-metals. They are
also known as semi-metals.
ELEMENT, PROPERTY AND EXAMPLES
Elements Property Examples
Metals Good conductor Iron, Tin, Lead, Zinc etc.
Metalloids Semi-Conductor of electricity Silicon, Boron, Arsenic,
Tellurium etc.
Non-metals Non-Conductor of electricity Oxygen, Chlorine, Hydrogen,
Argon, Bromine etc.
DIFFERENCES BETWEEN PHYSICAL PROPERTIES OF METALS AND NON-METALS
Metals Non-Metals
All metals except mercury are generally solids under
ordinary condition
Non-metals may be gases, e.g Oxygen, Hydrogen,
Argon etc.
Or liquid, e.g., bromine,
Or solid, e.g., carbon, sulphur etc.
Metals have high melting point and boiling point Non-metals except carbon have low melting and
boiling points.
Metals are good conductors of heat and electricity,
e.g. aluminium.
Non-metals except graphite are poor conductors of
heat and electricity
Metals are malleable i.e. can be hammered into
different shapes and are ductile, i.e. can be drawn
into thin wire.
Non-metals are brittle, i.e., cannot be hammered.
They possess characteristics lustre They do not possess characteristic lustre except
carbon.
They exist as crystal lattice held by strong metallic
bonds
Non-metals except diamond exist as covalent
molecules held together by weak forces.
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COMPOUNDS
A compound is a substance formed when two or more different elements are chemically joined together.
A compound is formed as a result of a chemical change, and it is a new substance with different
properties from the substance(s) from which it was formed.
The component elements of a compound are present in a fixed ratio by mass. For example, water is a
compound formed a result of chemical reaction among the compound elements, hydrogen and oxygen
in the ratio of 2 : 1 respectively
NOTE: There are two types of pure substance namely:
(i) An element
(ii) A compound:
Compounds Components Elements
Water, (H2O),
Sodium hydroxide, (NaOH)
Sodium chloride (NaCl)
Glucose,(C6H12O6)
Ethanol,(C2H5OH)
Calcium hydroxide, [Ca(OH)2]
Soap (C17H35COONa)
Sodiumtrioxocarbonate(IV)decahydrate,
(Na2CO3.10H2O)
Hydrogen, Oxygen
Sodium, Oxygen and Hydrogen.
Sodium, Chlorine.
Carbon, Hydrogen, and Oxygen.
Carbon, Hydrogen, and Oxygen.
Calcium, Oxygen and Hydrogen.
Carbon, Hydrogen, Oxygen and Sodium.
Sodium, Carbon, Oxygen and Hydrogen
MIXTURES
A mixture is a substance formed when two or more constituents are physically joined together. The
constituents of mixtures can be elements or compounds or both, and be separated by physical means,
since they are not chemically combined.
The constituents of a mixture retain their individual identities because their physical and chemical
properties are not changed by simple mixture.
TYPES OF MIXTURES
A mixture may be
Homogeneous or
Heterogeneous.
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Homogeneous mixtures is a uniform mixture, called solution and the single phase in which a solution
occurs may be gaseous, liquid or solid. A solution is made up of more than one substance, one being
uniformly dispersed in the other.
Heterogeneous mixture is a non-uniform mixture.
Pure substances are homogeneous materials that have fixed compositions and invariable intrinsic
properties.
EXAMPLES OF MIXTURES AND THEIR CONSTITUENTS
Mixtures Constituents
Air Oxygen, Carbon(IV)oxide, Nitrogen, Rare
gases, Dust and Moisture
Soil Sand, Clay, Humus, Water, Air and Mineral
salts.
Urine Urea, Water, Mineral salts.
Palm wine Water, Sugar, Alkanol, Mineral salts,
Vitamins, Yeast, Proteins
Milk Water, Sugar, Fat, Proteins, Mineral salts and
Vitamins
Sea water Water, Mineral salt, Bacterial, Remains of
organic matter
Blood
Water, proteins, Fat, Oil, Sugar, Mineral Salts
Vitamins, Hormones, Enzymes, Blood cells,
haemoglobin.
Petroleum Petrol, Heavy oil, Gas oil, Kerosene, Naphtha,
Bitumen, gas, etc.
Bronze Copper and Tin.
DIFFERENCES BETWEEN MIXTURES AND COMPOUNDS
Mixtures Compounds
1. It may be homogeneous or heterogeneous. It is always homogeneous
2. The constituents are not chemically bound
together and cannot be separated by physical
separated by physical means.
The component elements are chemically
bound together and can be easily means.
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3. The constituents can be together in any ratio
by mass. Hence, a mixture cannot be
represented by a chemical formula
The component elements are present in a fixed
ratio by mass. Hence, a com pound can be
represented by a chemical formula
4. The properties of mixture are the sum of
those of its individual constituents.
The properties of a compound differ entirely
from those of its component elements.
5. Mixture is not usually accompanied by
external effects such as explosion, evolution
of heat or volume change.
Usually accompanied by one or more of these
effects
NAMING OF COMPOUND USING IUPAC NOMENCLATURE
OBJECTIVES
At the end of this topic, you should be able to:
1. Define valency, radical and oxidation number
2. Use the knowledge of valency and radical to write the formula od an inorganic compound
3. Name an inorganic compound
VALENCY/OXIDATION NUMBER
VALENCY can be defined as the combining power of an element or radical.
OXIDATION NUMBER can be defined as the electrical charge it appears to have as determined by a
set of arbitrary rules
NOTE: Oxidation number and valency are similar in a way but the striking difference is that, valency
carries no sign of charge but oxidation number either carries a positive or negative charge. Metals carries
a positive sign while n on-metals carries negative
HOW TO CALCULATE OXIDATION NUMBER
The IUPAC system uses oxidation numbers in naming compounds. The following rules are employed
in calculating oxidation number
RULES FOR DETERMINING OXIDATION NUMBER
1. The oxidation number of all element/molecules in their free state is zero. e.g., Na, Cl2, Mg, P4
etc
2. The oxidation number of simple ions has the same size and sign as the charge of the ion. e.g.,
Na+, Mg2+, Cl- and S2- are +1, +2, +3, -1 and -2 respectively
3. The algebraic sum of oxidation number of all elements in a compound is zero. e.g., MgCl2 = 0,
H2SO4 = 0
4. The algebraic sum of the oxidation number of radicals has the size and sign as the charge of the
radical. e.g., SO42-, NH4
+, OH-, ClO3-, has oxidation number of -2, +1, -1 and -1 respectively
NOTE: in most compound, the oxidation number of oxygen is -2, (except in peroxide where it is -1)
while the oxidation number of hydrogen is +1 (except in hydride where it is -1)
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EXAMPLE:
1. Calculate the oxidation number of manganese in KMnO4
2. State the change in the oxidation number of Cu from the reaction below:
Cu → Cu2+
State the change in the oxidation number of Cu from the reaction below:
8H+ + MnO4- → Mn2+ + 4H2O
CLASS ACTIVITY
Find the oxidation number of the following marked element
i. H𝑁O3
ii. K2𝐶𝑟2O4
iii. [𝐹𝑒(CN)6]4-
iv. Na2𝑆O4
v. H2𝑆O4
vi.
The table below shows the oxidation number and valency of the first 20 elements
Element Symbol Oxidation
number
Valency
Hydrogen
Helium
Lithium
Beryllium
Boron
Carbon
Nitrogen
Oxygen
Fluorine
Neon
Sodium
Magnesium
Aluminium
Silicon
Phosphorus
H
He
Li
Be
B
C
N
O
F
Ne
Na
Mg
Al
Si
P
+1
0
+1
+2
+3
+2 or +4
-3 or +5
-2 or +6
-1 or +7
0
+1
+2
+3
+2 or +4
-3 or +5
1
0
1
2
3
2 or 4
3 or 5
2 or 6
1 or 7
0
1
2
3
2 or 4
3 or 5
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SS 1 CHEMISTRY BY OTEGA OMOYIBO (TEGAMATICS) 16
Sulphur
Chlorine
Argon
Potassium
Calcium
S
Cl
Ar
K
Ca
-2 or +6
-1 or +7
0
+1
+2
2 or 6
1 or 7
0
1
2
RADICALS
Radicals are groups of atom carrying and electrical charge and function as a single unit.
The table below shows some radicals, names oxidation number and valency
Name Formula Oxidation
number
Valency
Trioxonitrate (V)
Trioxochlorate (V)
Tetraoxomanganate (VII)
Hydroxide
Hydrogen trioxocarbonate (IV)
Hydrogen tetraoxosulphate (VI)
Trioxocarbonate (IV)
Tetraoxosulphate (VI)
Trioxosulphate (IV)
Tetraoxophosphate (V)
Ammonium
𝑁𝑂3−
𝐶𝑙𝑂3−
𝑀𝑛𝑂4−
𝑂𝐻−
𝐻𝐶𝑂3−
𝐻𝑆𝑂4−
𝐶𝑂32−
𝑆𝑂42−
𝑆𝑂32−
𝑃𝑂43−
𝑁𝐻4+
-1
-1
-1
-1
-1
-1
-2
-2
-2
-3
+1
1
1
1
1
1
1
2
2
2
3
1
ASSIGNMENT: Mention 7 other radicals, there formulas, oxidation number and valency
WRITING CHEMICAL FORMULAE
With the students' knowledge of the symbols for some elements, the oxidation numbers assigned to
them in their combined states and the valency, they are now better equipped to write the correct
formulae for some chemical compounds.
CHEMISTRY @ OLASS, YABA.
SS 1 CHEMISTRY BY OTEGA OMOYIBO (TEGAMATICS) 17
The following rules will guide the students in doing so:
Write the symbols for the element and radicals.
Write the oxidation valencies above and to the right of the symbols.
Rewrite the symbols, exchanging the valencies and write the number below and to the right of
the symbol
The number of atoms of the component elements in the formula must be written as a numerical
subscript after the element concerned. If a radical occurs more than once it must be enclosed
with a parentheses
Example: By applying the rules, the formulae of the following compounds can be written:
i. Sodium hydroxide
ii. Magnesium chloride
iii. Calcium trioxonitrate (V)
iv. Aluminium tetraoxosulphate (VI)
v. Sodim trioxocarbonate (IV)
vi. Ammonium tetraoxosulphate (VI)
vii. Calcium hydroxide
viii. Potassium trioxonitrate (V)
ix. Hydrogen tetraoxophate (V)
x. Potassium trioxochlorate (V)
xi. Ammonium chloride
xii. Magnesium oxide
xiii. Aluminium oxide
xiv. Sodium nitride
xv. Sodium floride
NAMING OF INORGANIC COMPOUND:
Inorganic compounds comprises of cations and anions.
The cations are usually named first before the anions
Cations are named the way they appear e.g, Na is named sodium, Ca is named calcium etc
There are ways we name anions: if the anion ends with ygen, ine the name ends with ide. For
example, oxygen is named oxide, chlorine is named chloride etc
Radicals are always names the way they appear in the radical table above
Binary compounds. Binary compounds contain two elements only. The metal is named first,
followed by the name of the second element ending with –ide. If the metal is one that has
variable valencies, the valency exhibited will be written in Roman numeral examples are given
below:
Name of compounds
Formula Conventional Name IUPAC Name
Na2O Sodium oxide
Fe2O3 Iron (III) oxide
CHEMISTRY @ OLASS, YABA.
SS 1 CHEMISTRY BY OTEGA OMOYIBO (TEGAMATICS) 18
CO Carbon monoxide Carbon (II) oxide
CO2 Carbon dioxide Carbon (IV) oxide
N2O Nitrous oxide Dinitrogen (I) oxide
EXAMPLE:
Name the following compound: NaOH, CaSO4, Al2O3, CaCl2, NH4NO3
Solutions:
NaOH = Sodium hydroxide
CaSO4 = Calcium tetraoxosulphate (VI)
Al2O3 = Aluminium oxide
CaCl2 = Calcium chloride
NH4NO3 = Ammonium trioxonitrate (V)
CLASS ACTIVITY
Name the following compound:
1. Na2CO3
2. K2SO4
3. H2O
4. H2SO4
5. Ca(NO3)2
6. NaCl
7. KF
8. NH4Cl
9. (NH4)2SO4
10. MgO
11. Al(NO3)3
12. KOH
13. HNO3
14. HCl
15. CaO