IRON (Fe) – At a glance

1. Basic Information 

Property	Information
Element	Iron
Symbol	Fe
Atomic number	26
Relative atomic mass	55.85
Group
Period	4
Block	d-block
Nature	Transition metal
Melting point	1538°C
Density	7.87 g/cm³

2. Occurrence of Iron

Iron occurs mainly in the Earth's crust as compounds called ores.

Iron ore	Chemical formula
Haematite	Fe₂O₃
Magnetite	Fe₃O₄
Siderite	FeCO₃
Limonite	Fe₂O₃·xH₂O
Iron pyrites	FeS₂

Most important ore: Haematite (Fe₂O₃).

Note: Iron pyrites is not an important commercial ore for iron extraction because of its high sulphur content.

3. Types of Iron

S/N	Type	Main characteristics
1.	Pig iron	Crude iron from the blast furnace; high carbon content
2.	Cast iron	Hard, brittle and easily cast
3.	Wrought iron	Very low carbon; tough and malleable
4.	Steel	Alloy of iron and carbon; strong and versatile

4. Physical Properties of Iron

1. Silvery-grey in colour.
2. Solid at room temperature.
3. Hard and strong.
4. Malleable – can be hammered into sheets.
5. Ductile – can be drawn into wires.
6. Magnetic – attracted by magnets.
7. Good conductor of heat and electricity.
8. High melting point (1538°C).
9. High density (7.87 g/cm³).
10. Sonorous.

5. Chemical Properties of Iron

Iron reacts with oxygen, water, acids and non-metals.

Reaction	Balanced chemical equation
With oxygen	3Fe + 2O₂ → Fe₃O₄
Rusting	4Fe + 3O₂ + 2xH₂O → 2Fe₂O₃·xH₂O
With steam	3Fe + 4H₂O → Fe₃O₄ + 4H₂
With hydrochloric acid	Fe + 2HCl → FeCl₂ + H₂
With sulphuric acid	Fe + H₂SO₄ → FeSO₄ + H₂
With sulphur	Fe + S → FeS
With chlorine	2Fe + 3Cl₂ → 2FeCl₃
With copper(II) sulphate	Fe + CuSO₄ → FeSO₄ + Cu

6. Rusting of Iron

Rusting is the slow reaction of iron with oxygen and moisture to form hydrated iron(III) oxide.

i. Colour of rust: Reddish-brown.

ii. Conditions required: Oxygen and water.

iii. Rust weakens iron objects.

Prevention of Rusting

1. Painting
2. Oiling and greasing
3. Galvanisation
4. Electroplating
5. Alloying to produce stainless steel
6. Plastic coating

7. Uses of Iron

Application	Use
1. Construction	Buildings, bridges and reinforcement bars
2.Transportation	Cars, ships and railway tracks
3. Agriculture	Hoes, cutlasses and ploughs
4. Manufacturing	Machines and industrial equipment
5. Household	Pots, pans, gates and doors
6. Electrical industry	Transformer cores and electromagnets
7. Plumbing	Pipes and drainage systems

8. Important Examination Facts

1. Symbol of iron: Fe.
2. Atomic number: 26.
3. Most important iron ore: Haematite.
4. Formula of haematite: Fe₂O₃.
5. Formula of magnetite: Fe₃O₄.
6. Formula of siderite: FeCO₃.
7. Formula of iron pyrites: FeS₂.
8. Main raw materials for blast furnace extraction: Iron ore, coke and limestone.
9. Reducing agent in the blast furnace: Carbon monoxide.
10. Flux used in iron extraction: Limestone.
11. Main slag formed: Calcium silicate (CaSiO₃).
12. Main product: Molten pig iron.
13. Common corrosion product: Hydrated iron(III) oxide.

9. Essential Chemical Equations

Reduction of iron ore:

Fe₂O₃ + 3CO → 2Fe + 3CO₂

Decomposition of limestone:

CaCO₃ → CaO + CO₂

Formation of slag:

CaO + SiO₂ → CaSiO₃

10. Quick Revision Questions

1. What is the chemical symbol of iron?
2. State the atomic number of iron.
3. Name four important ores of iron.
4. Which iron ore is represented by Fe₃O₄?
5. What is rusting?
6. State four methods of preventing rusting.
7. What is the difference between cast iron and wrought iron?
8. Which gas reduces iron ore in the blast furnace?
9. What is the function of limestone in iron extraction?
10. Write the equation for the reduction of haematite by carbon monoxide.

Remember: Iron is an important transition metal, and its major industrial importance comes from its use in producing steel and other useful alloys.

IRON note for students

 IRON (Fe)

1. Introduction

Iron is an important metallic element that is widely used in our everyday lives. It is used in the construction of buildings, bridges, railway lines, vehicles, machines and many other objects.

Iron is a transition metal with the chemical symbol Fe, derived from its Latin name, Ferrum. It has atomic number 26 and belongs to Group 8 of the periodic table.

Iron is one of the most abundant metals in the Earth's crust and is mainly obtained from its ores through extraction in a blast furnace.

2. Occurrence of Iron

Iron occurs naturally in the Earth's crust, mainly in the form of compounds called iron ores. It is rarely found in the free or uncombined state because it readily reacts with oxygen and other elements.

Some important iron ores include:

(a) Haematite

  i. Chemical formula: Fe₂O₃

ii.  It is reddish-brown in colour.

iii. It is one of the most important ores used in the extraction of iron.

(b) Magnetite

I. Chemical formula: Fe₃O₄

ii. It is black in colour.

iii. It is naturally magnetic and contains a high percentage of iron.

(c) Siderite

I. Chemical formula: FeCO₃

ii.  It is also known as iron carbonate.

iii.  It is usually brownish or greyish in appearance.

(d) Limonite

i.  Approximate formula: Fe₂O₃·xH₂O

ii. It is a hydrated iron(III) oxide.

iii. It is usually yellowish-brown.

(e) Iron Pyrites

i .Chemical formula: FeS₂

ii.  It is also called fool's gold because of its golden appearance.

iii.  It is not commonly used for iron extraction because of its high sulphur content.

3. Extraction of Iron

Iron is extracted from its ores, mainly haematite (Fe₂O₃), by heating the ore with coke and limestone in a large industrial furnace called a blast furnace.

The process involves the reduction of iron oxide by carbon monoxide.

(a) Raw Materials Used in the Extraction of Iron

The main raw materials are:

1. Iron ore (Haematite, Fe₂O₃): This is the source of iron.

2. Coke (Carbon, C): It serves as a fuel and helps produce carbon monoxide, which reduces the iron ore.

3. Limestone (Calcium carbonate, CaCO₃): It acts as a flux and helps remove impurities.

4. Hot air: It supplies oxygen for the combustion of coke.

(b) The Blast Furnace

A blast furnace is a tall, steel structure lined internally with heat-resistant bricks. It is used for extracting iron from iron ore.

The raw materials are charged into the furnace through the top, while hot air is blown in through openings called tuyeres, located near the bottom.

Animated illustration showing the extraction of iron from haematite in a blast furnace, including the major chemical reactions and separation of molten iron from slag.

The extraction of iron involves the following stages:

1. Combustion of Coke

Hot air is blown into the furnace through the tuyeres. 

At the bottom

Coke burns in oxygen to produce carbon dioxide and heat.

C + O₂ → CO₂

The heat produced raises the temperature inside the furnace.

The carbon dioxide produced reacts with more hot coke to form carbon monoxide.

CO₂ + C → 2CO

Carbon monoxide is the main reducing agent in the blast furnace.

At the middle 

2. Decomposition of Limestone

Limestone decomposes under the high temperature in the furnace to form calcium oxide and carbon dioxide.

CaCO₃ → CaO + CO₂

Calcium oxide acts as a flux.

Formation of Slag

The calcium oxide reacts with silica (sand), which is an impurity in the iron ore, to form calcium silicate.

CaO + SiO₂ → CaSiO₃

Calcium silicate is called slag.

At the top

3. Reduction of Iron Ore

Carbon monoxide reacts with haematite and removes oxygen from it, producing iron.

        Fe₂O₃ + 3CO → 2Fe + 3CO₂

The iron produced melts as it moves into the hotter lower region of the furnace.

6. Separation of Iron and Slag

Molten iron is denser than slag. Therefore, the molten iron collects at the bottom of the furnace, while the lighter molten slag floats above it.

The two products are removed through separate outlets.

(d) Products of the Blast Furnace

The main products are:

1. Molten pig iron: This is the main product. It contains iron, carbon and other impurities.

2. Slag (calcium silicate): This is a by-product formed when the flux combines with silica impurities.

3. Waste gases: These include carbon monoxide, carbon dioxide and nitrogen, among other gases.

(e) Functions of the Raw Materials

S/N	Raw material	Function
1.	Haematite	Source of iron
2.	Coke	Fuel and source of carbon (II) oxide
3.	Limestone	Remove silica impurities as slag
4.	Hot air	Supports combustion o

(f) Important Equations in Iron Extraction

1. Combustion of coke:

   

   C + O₂ → CO₂

2. Formation of carbon monoxide:

   

   CO₂ + C → 2CO

3. Reduction of haematite:

   

   Fe₂O₃ + 3CO → 2Fe + 3CO₂

4. Decomposition of limestone:

   

   CaCO₃ → CaO + CO₂

5. Formation of slag:

   

   CaO + SiO₂ → CaSiO₃

(g) Uses of Slag

i. It is used in road construction.

ii. It is used in the manufacture of some cement products.

iii. It is used as a construction material.

Note: The iron obtained directly from the blast furnace is called pig iron. It is further processed to produce cast iron and steel.

 

Types of Iron

Iron is classified into different forms according to its composition, carbon content and method of preparation.

1.  Pig Iron

Pig iron is the crude form of iron obtained directly from the blast furnace.

Characteristics:

i.  It contains about 3.5–4.5% carbon, although the composition varies.

ii. It contains impurities such as silicon, sulphur, phosphorus and manganese.

iii. It is hard and brittle.

iv.  It is mainly used as a raw material for producing cast iron and steel.

2. Cast Iron

Cast iron is produced by remelting pig iron and adjusting its composition.

Characteristics:

i. Generally contains about 2–4% carbon.

ii. It is hard but brittle.

iii.  It has good casting properties.

iv.  It is used in making engine blocks, pipes, manhole covers and machine parts.

3. Wrought Iron

Wrought iron is the purest form of iron containing very little carbon.

Characteristics:

I.  It contains less than about 0.1% carbon.

ii.  It is tough, malleable and ductile.

iii. It can be shaped by hammering.

iv. It is more resistant to corrosion than ordinary carbon steel, but it can still rust.

Uses 

include ornamental gates, railings and decorative metalwork.

(d) Steel

Steel is an alloy of iron and carbon, usually containing less than about 2% carbon.

Characteristics:

i. It is generally stronger and tougher than pure iron.

ii. Its properties depend on its carbon content and other alloying elements.

iii. It can be modified by adding elements such as chromium, nickel and manganese.

Uses

Steel is used in construction, vehicles, tools, machinery and household appliances.

Physical Properties of Iron

1. Iron is a silvery-grey metal with a shiny surface when freshly polished.

2. It is a solid at room temperature.

3. It is malleable; therefore, it can be hammered into sheets.

4. It is ductile and can be drawn into wires.

5. It is a good conductor of heat and electricity.

6. It is attracted by magnets and can be magnetised.

7. It has a relatively high melting point of about 1538°C.

8. It has a high density of approximately 7.87 g/cm³.

9. It is strong and hard compared with many common metals.

10. It is sonorous and produces a ringing sound when struck.

Chemical Properties of Iron

Iron is a moderately reactive metal. It reacts with oxygen, water, acids and some non-metals.

(a) Reaction with Oxygen

under suitable conditions, it forms iron oxides.

For example, iron reacts with oxygen to form magnetite:

3Fe + 2O₂ → Fe₃O₄

(b) Reaction with Moist Air (Rusting)

Iron reacts slowly with oxygen and moisture in the atmosphere to form rust.

Rust is a reddish-brown substance consisting mainly of hydrated iron(III) oxide.

General equation:

4Fe + 3O₂ + 2xH₂O → 2Fe₂O₃·xH₂O

Rusting weakens iron objects and gradually damages them.

(c) Reaction with Steam

When hot iron reacts with steam, magnetite and hydrogen gas are produced.

3Fe + 4H₂O(g) → Fe₃O₄ + 4H₂

(d) Reaction with Dilute Acids

Iron reacts with dilute hydrochloric acid to form iron(II) chloride and hydrogen gas.

Fe + 2HCl → FeCl₂ + H₂

It also reacts with dilute sulphuric acid:

Fe + H₂SO₄ → FeSO₄ + H₂

(e) Reaction with Sulphur

When iron combines with sulphur under suitable conditions, iron(II) sulphide is formed.

Fe + S → FeS

(f) Reaction with Chlorine

Iron reacts with chlorine to form iron(III) chloride.

2Fe + 3Cl₂ → 2FeCl₃

(g) Displacement Reaction

Iron is more reactive than copper. Therefore, it displaces copper from copper(II) sulphate solution.

Fe + CuSO₄ → FeSO₄ + Cu

The blue colour of copper(II) sulphate solution gradually changes to pale green as iron(II) sulphate forms, while copper is deposited.

6. Uses of Iron

Iron and its alloys have many important applications.

1. Construction: Steel is used in buildings, bridges, railway tracks and reinforcement bars.

2. Manufacturing: Iron is used in making machines, industrial equipment and tools.

3. Transportation: Iron and steel are used in manufacturing cars, ships, trains and other vehicles.

4. Household equipment: Iron and its alloys are used in making pots, pans, gates, doors and cooking equipment.

5. Agriculture: Iron is used in making hoes, cutlasses, ploughs and other farm implements.

6. Electrical industry: Special iron alloys are used in transformer cores and electromagnets.

7. Pipelines: Cast iron and other iron-based materials are used in water and drainage pipes.

8. Food production: Iron compounds are used in some food fortification products and nutritional supplements.

 Prevention of Rusting

Rusting can be prevented or reduced by keeping iron away from air and moisture or by protecting its surface.

Common methods include:

1. Painting: Applying paint prevents direct contact with air and moisture.

2. Oiling and greasing: A layer of oil or grease protects the metal surface.

3. Galvanisation: Coating iron or steel with zinc.

4. Electroplating: Coating iron with another metal such as chromium or tin.

5. Alloying: Adding chromium and other elements to produce stainless steel.

6. Plastic coating: Covering the surface with a protective plastic layer.

8. Summary

Iron is an important transition metal with the symbol Fe and atomic number 26. It occurs naturally in ores such as haematite, magnetite, siderite and limonite. Its common commercial forms include pig iron, cast iron, wrought iron and steel.

Iron is strong, malleable, ductile and magnetic. It reacts with oxygen, moisture, acids and non-metals. Its most common disadvantage is rusting, which can be controlled through protective coatings and alloying.

Objective Questions

1. The chemical symbol for iron is:

   A. Ir

   B. Fe

   C. In

   D. F

2. The principal ore used in the extraction of iron is:

   A. Bauxite

   B. Haematite

   C. Galena

   D. Cassiterite

3. The chemical formula of magnetite is:

   A. Fe₂O₃

   B. FeCO₃

   C. Fe₃O₄

   D. FeS₂

4. The process by which iron reacts with moist air to form rust is called:

   A. Reduction

   B. Neutralisation

   C. Rusting

   D. Electrolysis

5. The major component of steel is:

   A. Copper

   B. Iron

   C. Aluminium

   D. Zinc

6. Which of the following is a method of preventing rusting?

   A. Exposing iron to moisture

   B. Galvanisation

   C. Adding salt water

   D. Heating in air

7. The gas produced when iron reacts with dilute hydrochloric acid is:

   A. Oxygen

   B. Nitrogen

   C. Hydrogen

   D. Chlorine

8. Iron displaces copper from copper(II) sulphate because iron is:

   A. Less reactive than copper

   B. More reactive than copper

   C. A non-metal

   D. Chemically inert

Theory Questions

1. (a) What is iron?

   (b) State four iron ores and their chemical formulae.

2. (a) State five physical properties of iron.

   (b) Give three chemical properties of iron with balanced equations.

3. Explain four methods of preventing rusting.

4. Differentiate between pig iron, cast iron, wrought iron and steel.

5. State five important uses of iron and its alloys.

CHEMISTRY FAIR AND CAREER DAY at a glance

1. What is a Chemistry Fair?

A chemistry fair is an educational event where students display scientific projects, experiments, chemical products and practical applications of chemistry to demonstrate what they have learnt.

2. What is a Career Day?

A career day is an organised school event that introduces students to different professions and helps them understand career opportunities related to their interests and abilities.

 3. Importance of a Chemistry Fair

A chemistry fair helps students to:

1. Develop practical scientific skills.

2. Apply classroom knowledge to real-life situations.

3. Develop creativity and innovation.

4. Improve teamwork and communication skills.

5. Develop problem-solving abilities.

6. Appreciate the importance of chemistry in everyday life.

7. Discover science-related career opportunities.

4. Examples of Chemistry Fair Projects

Students can display or demonstrate:

- Production of liquid soap.

- Preparation of emulsion paint.

- Production of air fresheners.

- Water purification.

- Separation of mixtures.

- Testing of acids and bases.

- Preparation of natural indicators.

- Demonstration of chemical reactions.

 5. Chemistry-Related Careers

| Career | Main Area of Work |

|---|---|

| Chemist | Studies substances and chemical reactions. |

| Chemical Engineer | Designs chemical production processes. |

| Pharmacist | Prepares and dispenses medicines. |

| Medical Laboratory Scientist | Analyses laboratory samples. |

| Food Scientist | Studies food quality and preservation. |

| Environmental Scientist | Studies and protects the environment. |

| Chemistry Teacher | Teaches chemistry. |

| Industrial Chemist | Applies chemistry in manufacturing industries. |

| Forensic Scientist | Uses scientific methods to examine evidence. |

| Petroleum Chemist | Studies petroleum and its products. |

 6. Importance of Chemistry to Society

Chemistry contributes to national development through:

Medicine: Production of drugs and pharmaceutical products.

Agriculture: Production of fertilisers and pesticides.

Industry: Manufacture of paints, plastics, soaps and detergents.

Environment: Water treatment and pollution control.

Food: Food processing, preservation and quality control.

Energy: Development of fuels and alternative energy materials.

7. Skills Developed Through Chemistry Fairs

i. Creativity

ii. Critical thinking

iii. Teamwork

iv. Communication

iv. Observation

v. Problem-solving

 vi.Practical skills

- Entrepreneurship

8. Safety Rules During Chemistry Fairs

1. Wear appropriate protective clothing, including laboratory 2coats and safety goggles where necessary.

2. Do not taste or directly smell chemicals.

3. Handle chemicals and laboratory equipment carefully.

4. Avoid mixing unknown chemicals.

5. Keep the exhibition area clean and organised.

6. Ensure that demonstrations are supervised by a qualified teacher.

7. Dispose of chemical waste properly.

9. Key Terms to Remember

Chemistry Fair:  An exhibition of chemistry projects and experiments.

Career Day: An event that introduces students to different professions.

Innovation: Development of new ideas, methods or products.

Entrepreneurship: The ability to identify business opportunities and establish businesses.

Chemical Industry: An industry involved in producing chemicals and chemical products.

National Development: Improvement in the economic, social and technological well-being of a country.

 A. Objective Questions

1. A chemistry fair provides students with an opportunity to ______.

   A. avoid practical work

   B. display scientific projects

   C. memorise chemical symbols only

   D. stop learning chemistry

2. Which of the following is a chemistry-related career?

   A. Chemist

   B. Tailor

   C. Footballer

   D. Musician

3. The production of fertilisers is an application of chemistry in ______.

   A. transportation

   B. agriculture

   C. entertainment

   D. sports

4. Which skill is developed through participation in chemistry fairs?

   A. Creativity

   B. Laziness

   C. Carelessness

   D. Dishonesty

5. A person who designs chemical production processes is a ______.

   A. historian

   B. chemical engineer

   C. journalist

   D. banker

 Theory Questions

1. Define a chemistry fair.

2. State five importance of organising a chemistry fair in schools.

3. Mention five chemistry-related careers.

4. Explain four ways chemistry contributes to national development.

5. State five safety rules that should be observed during a chemistry fair.

REMEMBER!

Chemistry is not just a subject studied in the classroom. It is a practical science that contributes to medicine, agriculture, industries, environmental protection and national development.

NATURE OF MATER

What is Matter: -
 Mater is defined as anything that has mass and occupies space.

Mass refers to the amount of substance present, while space occupied by matter is known as volume.

Examples of Matter

• Air inside a balloon
  

1. Liquid in a container 
2. Sand on a beach 
3. wooden table

All these substances have mass and occupy space, therefore they are matter.

Composition of matter: - matter consist of any one of the following particles. 

1. Atoms.  

2. Molecules.  Or

 3. Ions

1. An Atom is the smallest particle of an element that can take part in a chemical reaction.

2. A molecule is the smallest particle of a substance that exist alone and sc8jnn̈n ib bib jb ib j j nj i. In  i j.  Jtill possess the properties of the substance. E.g H₂O, 

3. An Ion is a charged particle; it is formed when an atom loses or gains electrons.  E.g Na+, Cl- 

Radicals are group of atoms with a single charge.  E.g NO-, SO₄^2-, OH-

Matter generally is made up of any one or more of the particles mentioned above.

States of matter

matter can exist in three states.

i. the solid

ii. the liquid and

iii. the gaseous state.

SOLID: - In solids the particles of matter are densely packed and are held by strong forces of attraction (force of cohesion).

Properties of solids 

i., solids have fixed, or definite volumes

ii. solids also have fixed shapes.

iii solids cannot be compressed

                           

Solid state (particles are tightly packed and are held by strong forces) 

LIQUIDS: -In liquids the molecules (particles) are close together in an orderly manner with little freedom of movement.  Molecules in a liquid are close together but are not held so tightly in position and so can move past one another.

Properties of Liquids

i.  a liquid no fixed or definite shape but it takes the shape of its container, 

ii. liquids have a fixed or definite volume 

iii. liquids cannot be compressed.

                    

Liquid state (particles are not held tightly together)

GAS: - In a gas, the particles/molecules are separated by distances that are large compared with the size of the molecules.

Properties of gases

i. gasses have no fixed or definite volume (but occupy entire volume of its container) 

ii. gases have no fixed shape.

iii.   gases can be compressed

 Gases differ from liquids and solids in the distances between their individual particles.

        Gases (particles of gases are wide apart)

The three states of matter can be inter-convertible without changing the composition of the substance. When we heat a solid it will change into a liquid form at a particular temperature.

The temperature at which this change occurs is called the melting point of the solid. If the heating continues it will convert the liquid into a gas at a particular temperature called the boiling point of the liquid. 

Cooling a gas on the other hand, will cause it to change into a liquid, this process is called Condensation. When the liquid is cooled further, it will change into the solid form, and the process is known as Freezing. 

Some solids change directly to the gaseous without passing through the liquid state and vice Versal. These processes are both known Sublimation and Deposition.

              Changes in the state of Matter

 

  Matter can change from one state to another when heat energy is added or removed.

Changes in the State of Matter

Change	Description	Example
Melting	Solid → Liquid	Ice turning to water
Freezing	Liquid → Solid	Water forming ice
Evaporation	Liquid → Gas	Water forming vapor
Condensation	Gas → Liquid	Steam forming water droplets
Sublimation	Solid → Gas directly	Camphor or naphthalene

PROPERTIES OF MATTER 

    The properties of matter can be grouped into two

1.  Physical properties

2. Chemical properties 

1. Physical properties:-  those properties that a substance (matter) shows by itself (i.e those properties that you see when you look at, touch or smell the substance) these include Temperature, Pressure, Colour, Smell, Density, Solubility, Melting and boiling points.

ii. Chemical properties on the other hand are those properties that matter exhibits when it comes in contact with other substances like acids, bases, even water to form new substances.

Physical and Chemical change

A physical change is a change that is easily reversible and in which no new substance is formed.

example of physical changes is.

9i. Dissolving sodium chloride in water

ii. Changing water to ice

iii. Evaporation of liquids

iv. Melting of candle wax

A chemical change is one which is not easily reversible and in which a new substance is always formed.

example of changes is.

i.   burning of wood, paper, or clothe.

ii.  rusting of iron when exposed to air and moisture.

iii. decomposition of organic matter.

iv. dissolving a metal like calcium or magnesium in dilute acids.

v.   the hardening of cement   when exposed to air.

Importance of Studying the Nature of Matter

Understanding the nature of matter helps us to:

• Understand chemical reactions
• Study properties of substances
• Explain changes of state
• Develop new materials and medicines
• Improve processes in industry and technology

It is also important in fields like medicine, environmental science, engineering, and materials science.

Conclusion

The nature of matter explains the structure, properties, and behavior of substances. Since matter is made up of tiny particles that are constantly moving and attracting each other, many natural phenomena such as diffusion, evaporation, and chemical reactions can be 

Objectives Questions 

1. Matter is anything that has ______ and occupies space.
2. The space occupied by matter is called ______.
3. The smallest particles that make up matter are called ______.
4. The state of matter with definite shape and volume is ______.
5. The process by which a liquid changes to gas is called ______.

Section B

1. Which of the following is a physical change 

a). Dissolving sugar on water

b). Addition of acid to base 

c). Burñing of wood

d). Rusting of iron

2. Which of the following is not an example of matter? A. Water

B. Air

C. Heat

D. Iron

3. The three common states of matter are: 

A. Solid, liquid and gas

B. Solid, vapour and plasma

C. Liquid, gas and steam

D. Ice, water and vapour

4. Which state of matter has a definite shape and a definite volume? 

A. Gas

B. Liquid

C. Solid

D. Plasma

5. Which state of matter has a definite volume but no definite shape? A. Solid

B. Liquid

C. Gas

D. Vapour

6. Which state of matter has neither a definite shape nor a definite volume? A. Solid

B. Liquid

C. Gas

D. Ice

7. The particles in a solid are: A. Far apart and move freely

B. Closely packed and vibrate about fixed positions

C. Randomly arranged with large spaces

D. Completely stationary

8. Diffusion occurs fastest in: 

A. Solids

B. Liquids

C. Gases

D. Crystals

9. Brownian motion provides evidence that: A. Matter is colourful

B. Particles of matter are in constant motion

C. Solids are heavy

D. Liquids have fixed shapes

10. The process by which a solid changes directly into a gas is called: A. Melting

B. Evaporation

C. Condensation

D. Sublimation

11. Which of the following substances sublimes? 

A. Sodium chloride

B. Iodine crystals

C. Sand

D. Calcium carbonate

12. The change of a liquid into a gas at all temperatures is known as: 

A. Boiling

B. Freezing

C. Evaporation

D. Condensation

13. The conversion of a gas into a liquid is called: 

A. Melting

B. Condensation

C. Sublimation

D. Freezing

14. The kinetic theory states that matter is made up of: A. Cells

B. Atoms only

C. Tiny particles in constant motion

D. Molecules 

15. Which property of gases is due to the large spaces between their particles? 

A. High density

B. Fixed shape

C. Compressibility

D. Hardness

16. Which of the following is an example of diffusion? A. Ice melting

B. Sugar dissolving and spreading in water

C. Water freezing

D. Boiling water

17. Heating a solid generally causes its particles to: 

A. Stop moving

B. Move more slowly

C. Gain kinetic energy and move faster

D. Become smaller

18. Which state of matter has the highest kinetic energy of particles? 

A. Solid

B. Liquid

C. Gas

D. Ice

19. The force of attraction between particles is strongest in: A. Gases

B. Liquids

C. Solids

D. Vapours

20. Which of the following statements is correct? A. Matter cannot change from one state to another.

B. Gases have definite shapes.

C. Matter is composed of tiny particles.

D. Liquids have no volume.

Theory Questions

1. Explain the particle nature of matter.
2. Describe the three states of matter.
3. Explain two changes of state with examples. 

1(i). State two differences between the properties of solids and gasses

 (ii). What process does each of X, Y and Z represent in the changes 

ISOMERISM at a glance

Isomerism is defined as the occurrence of two or more compounds with the same molecular formular but different molecular structures. 

The different molecular structures are known as Isomers.
Isomers may belong to the same homologous series ( having the same functional group) or may belong to different homologous series (having different functional group)

Isomers with the same functional group, (i.e. belonging to the same homologous series) have similar chemical properties while isomers having different functional group (i.e. belonging to different homologous series) have different physical and chemical properties.

Example:- the formula C₂H₆O has two isomers 
1. Ethanol an Alkanol with molecular formula CH₃CH₂OH has a melting point of 78⁰C and is a liquid at room temperature 

     H   H
      |   |
H--C--C--OH
      |   |
     H   H

and 

2. an Alkoxy compound with molecular formula CH₃OCH₃ which is a gaseous at room temperature

      H       H
      |         |
H--C--O--C--H
      |       |
      H       H

TYPES OF ISOMERISM

(i) Structural isomerism
(ii) Stereo or geometric Isomerism
(iii) Optical isomerism
 
(I) Structural isomerism 

This is the occurrence of two or more compounds with the same molecular formula but different molecular structures 

Types of structural isomerism 

(a) Chain isomerism: in this case, the isomer differs in the way the carbon atoms are arranged in the molecule. Eg

    CH₃CH₂CH₂CH₃         

          n-butane

   CH₃CHCH₃

            ꘡

           CH₃

            

            2-methylpropane (isobutane)

(‘n’ stands for the normal compound while ‘iso’ means the isomer of the normal compound).

GROUP II METALS — AT A GLANCE

Also called: Alkaline Earth Metals

 Members:
Beryllium (Be) →Magnesium (Mg) → Calcium (Ca) → Strontium (Sr) → Barium (Ba) → Random (Ra)

Why are they called Group II metals?

They have two electrons in their outermost shell and commonly lose these electrons to form M²⁺ ions.

Example:

Ca → Ca²⁺ + 2e⁻

General Properties

i. Have 2 valence electrons

ii. Form M²⁺ ions

iii. Good conductors of heat and electricity

iv. Generally form ionic compounds

v. Reactivity generally increases down the group

vi. Their oxides and hydroxides are generally basic

vii. React with acids to produce salt + hydrogen

viii. Some react with water to produce metal hydroxide + hydrogen

CALCIUM — Ca

Quick identity

Symbol: Ca
Atomic number: 20
Group: II
Common ion: Ca²⁺

Electronic configuration: 1s22s22p63s23p64s2

Calcium is a reactive metal, so you will not normally find it as free calcium in nature. Instead, it occurs combined with other elements.

OCCURRENCE

Important calcium minerals (Ores) include:

Mineral	Formula
Limestone	CaCO₃
Chalk	CaCO₃
Marble	CaCO₃
Gypsum	CaSO₄·2H₂O
Fluorite	CaF₂
Dolomite	CaMg(CO₃)₂

NOTE 

 Limestone, chalk and marble are mainly forms of calcium carbonate, CaCO₃.

 EXTRACTION OF CALCIUM

Calcium is too reactive to be extracted by heating its compounds with carbon.

It is extracted by electrolysis of molten calcium chloride. CaF2 is added to lower its melting point

Diagram: Electrolytic cell of extraction of Calcium 

Electrolyte-:  Molten CaCl₂

At the cathode

Calcium ions gain electrons:

Ca²⁺ + 2e⁻ → Ca

At the anode-: Chloride ions lose electrons:

2Cl⁻ → Cl₂ + 2e⁻

Overall reaction

CaCl₂(l) → Ca(s) + Cl₂(g)

 Note

Calcium is extracted by electrolysis, not by carbon reduction.

Physical properties

Calcium is:

1.  Silvery-white

2. Relatively soft

3. A good conductor of heat and electricity

4. Less dense than many common metals

Chemical properties

1. Reaction with water

Ca + 2H₂O → Ca(OH)₂ + H₂

2. Reaction with oxygen: calcium tarnished in air when exposed to atmospheric gasses

2Ca + O₂ → 2CaO

3. Reaction with hydrochloric acid

Ca + 2HCl → CaCl₂ + H₂

4. Reaction with chlorine

Ca + Cl₂ → CaCl₂

USES OF CALCIUM 

Calcium compounds are more commonly used than calcium metal.

They are used in:

1. Manufacture of cement

2. Production of lime

3. Treatment of acidic soils

4. Manufacture of plaster

5. Building materials

6. Various industrial processes

Calcium is also an essential mineral for bones and teeth.

           Compounds of Calcium

Calcium compound	Formula	Method of preparation	Uses
Calcium oxide (quicklime)	CaO	By heating limestone strongly: CaCO₃ → CaO + CO₂	Manufacture of cement; neutralising acidic soils; production of calcium hydroxide; extraction of some metals
Calcium hydroxide (slaked lime)	Ca(OH)₂	By adding water to calcium oxide: CaO + H₂O → Ca(OH)₂	Making mortar and plaster; neutralising acidic soils; manufacture of bleaching powder; testing for CO₂
Calcium carbonate	CaCO₃	Precipitation by passing CO₂ into limewater or by reacting calcium hydroxide with a soluble carbonate	Manufacture of cement and lime; production of glass; used as a building material; manufacture of chalk
Calcium chloride	CaCl₂	By reacting calcium carbonate with hydrochloric acid: CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂	Drying agent; removal of ice from roads; dust control; used in laboratories and industry
Calcium sulphate	CaSO₄	Neutralization reaction.reacting calcium carbonate with dilute sulphuric acid:	Manufacture of plaster of Paris; making casts; construction materials
Calcium sulphate hemihydrate (Plaster of Paris)	CaSO₄·½H₂O	By heating gypsum, CaSO₄·2H₂O, at about 120°C:	Medical casts; moulds; decorative work; making models
Calcium sulphate dihydrate (Gypsum)	CaSO₄·2H₂O	Obtained naturally as the mineral gypsum;	Manufacture of plaster of Paris; cement manufacture; production of wallboard
Calcium carbide	CaC₂	By heating calcium oxide with carbon in an electric furnace: CaO + 3C → CaC₂ + CO	Production of ethyne (acetylene); metal cutting and welding; production of some chemicals
Calcium nitrate	Ca(NO₃)₂	Neutralization reacting calcium carbonate with nitric acid:	Nitrogen fertiliser; manufacture of explosives and other chemicals
Calcium phosphate	Ca₃(PO₄)₂	Prepared by reacting a soluble calcium salt with a soluble phosphate, producing a precipitate	Manufacture of fertilisers; production of phosphoric compounds; important component of bones and teeth

Introduction to Chemistry at a glance.

Definition of Chemistry

Chemistry is the branch of science that studies the composition, structure, properties, and changes of matter.

What is Matter?

Matter is anything that has mass and occupies space. Examples include air, water, wood, iron, and plastic.

Importance of Chemistry

Chemistry is important because it 

i. Helps us understand the materials around us.

ii. It is used in the production of medicines.

iii. It is important in agriculture through the manufacture of fertilizers and pesticides.

iv. Helps in making soaps, paints, plastics, cosmetics, and detergents.

v. Is applied in food processing and preservation.

vi. Contributes to environmental protection and pollution control.

Disadvantages of Chemistry

Although chemistry offers many benefits, it can also have negative effects when chemicals are misused, mishandled, or disposed of improperly.

1. Environmental Pollution: Some chemicals can contaminate the air, water, and soil.

2. Health Hazards: Exposure to toxic chemicals may cause poisoning, burns, allergic reactions, or disease.

3. Accidents: Improper handling of chemicals can result in fires, explosions, and laboratory accidents.

4. Production of Harmful Substances: Chemistry can be used to produce dangerous drugs, poisons, and chemical weapons.

5. Damage to the Ozone Layer: Certain chemicals, including chlorofluorocarbons (CFCs), contribute to the depletion of the ozone layer.

6. Climate Change: Some industrial chemicals release greenhouse gases, which contribute to global warming.

7. Food and Water Contamination: The excessive use of fertilizers and pesticides can contaminate food and water sources.

Branches of Chemistry

1. Organic Chemistry -: Study of carbon and its compounds.

2. Inorganic Chemistry -: Study of all other elements and their compounds.

3. Physical Chemistry -: Study of energy and the rate of chemical reactions.

4. Analytical Chemistry -: Identification and determination of substances in a sample.

5. Biochemistry -: Study of chemical processes in living organisms.

Key Terms

• Chemistry: Study of matter and its changes.

• Matter: Anything that has mass and occupies space.

• Atom: The smallest particle of an element.

• Molecule: Two or more atoms chemically combined.

Summary

Chemistry is the study of matter and the changes it undergoes. It plays an important role in medicine, agriculture, industry, and everyday life. Understanding chemistry helps us explain many natural and industrial processes.

Objective Questions

1. Chemistry is the branch of science that studies the ______.                                                                                    A. movement of planets
   B. composition, properties and changes of matter
   C. behaviour of animals
   D. structure of the earth
   
   

2. Anything that has mass and occupies space is called ______.                                                                                  A. energy
   B. matter
   C. force
   D. heat
   
   

3. The study of carbon compounds is known as ______ chemistry.                                                                              A. inorganic
   B. physical
   C. organic
   D. analytical
   
   

4. The branch of Chemistry concerned with the identification and determination of substances is ______.                                                                                  A. analytical chemistry
   B. organic chemistry
   C. biochemistry
   D. inorganic chemistry
   
   

5. The study of chemical processes occurring in living organisms is called ______.                                              A. physical chemistry
   B. biochemistry
   C. analytical chemistry
   D. nuclear chemistry
   
   

6. Which of the following is NOT a branch of Chemistry? A. Organic Chemistry
   B. Inorganic Chemistry
   C. Physical Chemistry
   D. Geographical Chemistry
   
   

7. One important use of Chemistry in agriculture is the production of ______.                                                          A. fertilizers
   B. computers
   C. buildings
   D. vehicles
   
   

8. Chemistry is important in medicine because it helps in the production of ______.                                                  A. medicines and drugs
   B. roads
   C. furniture
   D. clothes
   
   

9. Which of the following is a product of Chemistry commonly used at home?                                                A. Soap
   B. Stone
   C. Sand
   D. Wood
   
   

10. The study of energy changes and rates of chemical reactions belongs mainly to ______ chemistry.              A. organic
    B. physical
    C. analytical
    D. biochemistry
    
    

11. The early practice that contributed to the development of modern Chemistry was ______.                                    A. alchemy
    B. geography
    C. astronomy
    D. agriculture
    
    

12. The ancient practice of alchemy was concerned with attempts to ______.                                                            A. study weather patterns
    B. transform substances and discover useful materials
    C. study living organisms only
    D. build machines
    
    

13. A major contribution of early chemists to modern Chemistry was the development of ______.                    A. experimental methods
    B. football
    C. transportation
    D. architecture
    
    

14. Which of the following is a disadvantage of Chemistry? A. Production of medicines
    B. Environmental pollution
    C. Production of fertilizers
    D. Food preservation
    
    

15. Improper disposal of chemicals can lead to ______.      A. environmental pollution
    B. better soil automatically
    C. cleaner water
    D. increased rainfall
    
    

16. Exposure to toxic chemicals may cause ______.            A. health hazards
    B. better eyesight
    C. increased height
    D. improved hearing
    
    

17. The careless handling of chemicals may result in ______.                                                                                  A. accidents
    B. food production
    C. education
    D. transportation
    
    

18. Excessive use of pesticides and fertilizers may result in ______.                                                                              A. contamination of food and water
    B. production of oxygen
    C. cleaner rivers
    D. reduced pollution 
    

 Theory Questions

Answer all questions.

1. (a)i. Define Chemistry.
   ii.  What is matter

 iii. Give three examples of matter.

2. (a)i.  Mention five branches of Chemistry.
   ii. State one area of study for each branch mentioned.
   
   iii.  Mention two ways in which Chemistry has developed from early times to modern times.
   
   

3. (a).State five importance of Chemistry in everyday life.
   (b). State five disadvantages of Chemistry and explain how any two can be reduced or prevented.
   
   

At a glance revision for Ethical Legal and Social Issues in Chemistry

AT-A-GLANCE REVISION

Area	What should we consider?
Laboratory	Safety and responsible experimentation
Chemical waste	Proper treatment and disposal
Pollution	Protection of air, water and soil
Agriculture	Responsible use of fertilizers and pesticides
Medicines	Safety, correct use and access
Food	Safety, additives and adulteration
Industry	Worker, consumer and environmental protection
Research	Honesty and scientific integrity
Law	Compliance with chemical regulations
Technology	Benefits, risks and social effects
Green chemistry	Prevention of waste and hazards
Sustainability	Protecting resources for future generations

ETHICAL, LEGAL AND SOCIAL ISSUES IN CHEMISTRY

Introduction

When most students hear the word Chemistry, they immediately think about atoms, equations, acids, bases, salts, organic compounds and laboratory experiments.

But chemistry is much more than that.

Look around you. The soap you use to wash your hands, the paint on your house, the medicine you take when you are sick, the fertilizer farmers use, the fuel in vehicles and even the plastic bottles we use every day are all connected to chemistry.

Chemistry has made life easier in many ways. However, the same chemical knowledge that can be used to produce useful materials can also cause harm if it is misused.

This brings us to an important question:

How should we use chemistry in a way that benefits people without unnecessarily harming people or the environment?

This is where ethical, legal and social issues in chemistry come in.

1. UNDERSTANDING ETHICAL, LEGAL AND SOCIAL ISSUES

What is Ethics?

Ethics is simply about doing what is right, responsible and fair.

In chemistry, it means that a scientist, teacher, student, manufacturer or anyone working with chemicals should think about the possible consequences of their actions.

For example, imagine that a factory produces a chemical product and generates wastewater.

The factory has two choices:

• Treat the wastewater before releasing it, or

• Pour the untreated waste into a nearby river because it is cheaper.

Although dumping the waste may appear to save money, it can harm people who depend on the river and can also kill aquatic organisms.

The responsible choice is to manage the waste properly.

Ethical Behaviour in Chemistry

A responsible chemist should:

• Be honest when recording experimental results.

• Follow safety procedures.

• Properly label chemicals.

• Avoid unnecessary risks.

• Dispose of chemical waste properly.

• Protect people and the environment.

• Give accurate information about chemical products.

• Admit mistakes rather than hiding them.

Think About It

If an experiment gives you a result different from what you expected, should you change the result so that it agrees with your textbook?

No.

A scientist should record the result obtained and investigate why it was different.

That is scientific honesty.

2. CHEMICAL SAFETY AND RESPONSIBILITY

Chemicals are useful, but not every chemical is harmless.

Some chemicals can burn the skin, damage the eyes, cause poisoning, catch fire or harm the environment.

This is why chemical safety is everyone's responsibility.

It is not enough to say, "I didn't know the chemical was dangerous."

Before using a chemical, we should know:

• What the chemical is.

• What hazards it presents.

• How it should be handled.

• How it should be stored.

• What protective equipment is needed.

• What to do if there is a spill or exposure.

• How it should be disposed of.

Basic Laboratory Safety

Students should:

1. Read chemical labels before use.

2. Follow the teacher's instructions.

3. Wear appropriate protective equipment.

4. Never taste laboratory chemicals.

5. Avoid directly inhaling chemicals.

6. Keep chemicals in properly labelled containers.

7. Never mix chemicals unless instructed to do so.

8. Report accidents and spills immediately.

9. Wash hands after practical work.

10. Keep the laboratory clean and organized.

A Simple Example

Suppose two bottles are placed on a laboratory shelf. One contains water and the other contains a corrosive chemical.

If neither bottle is labelled, someone could easily use the wrong one.

Proper labelling is therefore not just a formality—it can prevent accidents.

3. CHEMICAL WASTE AND THE ENVIRONMENT

One of the biggest responsibilities associated with chemistry is deciding what to do with unwanted chemicals.

Chemical waste should not simply be poured into a gutter, dumped on the ground or released into a river.

What Can Happen?

Improper disposal of chemical waste can cause:

• Water pollution

• Soil contamination

• Air pollution

• Poisoning of aquatic organisms

• Damage to plants

• Health problems in humans

• Long-term environmental damage

Think About It

Imagine a community where people depend on a river for fishing and other activities.

If a factory continually releases untreated chemical waste into that river, who is affected?

The answer is everyone—the fishermen, families, farmers, animals and the environment.

This shows why chemical decisions can become social issues.

4. CHEMISTRY AND ENVIRONMENTAL POLLUTION

What is Pollution?

Pollution occurs when harmful substances or forms of energy enter the environment and cause undesirable effects.

Chemistry helps us understand many of the pollutants responsible for environmental problems.

Air Pollution

Some important air pollutants include:

• Carbon monoxide, CO

• Sulfur dioxide, SO₂

• Nitrogen oxides, NOₓ

• Particulate matter

• Some volatile organic compounds

They may come from vehicles, industries, burning fuels and other human activities.

Possible Effects

Air pollution can contribute to:

• Respiratory problems

• Smog

• Acid rain

• Environmental damage

• Climate-related problems

Water Pollution

Water can become polluted through:

• Industrial waste

• Sewage

• Oil pollution

• Agricultural chemicals

• Improper disposal of waste

Polluted water can affect both humans and aquatic life.

Effects May Include

• Death of aquatic organisms

• Unsafe drinking water

• Spread of disease

• Reduced water quality

• Eutrophication

Soil Pollution

Soil can become contaminated through:

• Excessive pesticide use

• Industrial waste

• Oil contamination

• Heavy metals

• Improper chemical disposal

Once harmful substances enter the soil, they may remain there for a long time and can sometimes enter food chains.

5. CHEMISTRY AND CLIMATE CHANGE

Have you ever wondered why scientists are concerned about increasing global temperatures?

Chemistry helps us understand part of the answer.

Some gases in the atmosphere absorb and re-emit infrared radiation. These are known as greenhouse gases.

Important greenhouse gases include:

• Carbon dioxide, CO₂

• Methane, CH₄

• Nitrous oxide, N₂O

• Water vapour

Human activities such as burning fossil fuels can increase the concentration of some greenhouse gases.

What Can Chemistry Do?

Chemists help develop:

• Cleaner fuels

• Better batteries

• Solar-cell materials

• More efficient industrial processes

• Improved methods of reducing emissions

• Materials that require less energy to produce

So chemistry is not only part of the problem—it is also part of the solution.

6. CHEMISTRY IN AGRICULTURE

Agriculture and chemistry are closely connected.

Farmers use chemical substances such as fertilizers, herbicides, insecticides and fungicides to improve crop production and control pests.

Fertilizers

Plants need nutrients such as:

• Nitrogen

• Phosphorus

• Potassium

Fertilizers can help replace nutrients in soil and improve crop growth.

However, using too much fertilizer can create problems.

Nutrients washed into rivers and lakes can contribute to eutrophication, which can seriously affect aquatic ecosystems.

Therefore:

The question is not whether fertilizers are good or bad. The important question is whether they are being used correctly and responsibly.

7. PESTICIDES AND THEIR SOCIAL EFFECTS

Pesticides are substances used to control unwanted organisms.

Examples include:

• Insecticides – control insects

• Herbicides – control unwanted plants

• Fungicides – control fungi

Why Are Pesticides Useful?

They can:

• Protect crops.

• Reduce losses caused by pests.

• Improve agricultural productivity.

What Are the Concerns?

Incorrect use can result in:

• Exposure of people to chemicals

• Contamination of soil and water

• Harm to non-target organisms

• Chemical residues

• Pesticide resistance

Farmers should therefore follow approved directions and safety requirements.

Think About It

Would it be responsible to use more pesticide simply because you think "more chemical means better protection"?

No.

Using a chemical beyond the appropriate amount can increase risks without necessarily producing better results.

8. CHEMISTRY, DRUGS AND HUMAN HEALTH

Chemistry plays an important role in the development, manufacture and testing of medicines.

Medicines have helped millions of people manage and treat diseases.

However, medicines must be used responsibly.

Important Issues Include:

• Safety testing

• Correct dosage

• Accurate labelling

• Proper storage

• Drug interactions

• Counterfeit medicines

• Drug misuse

• Antimicrobial resistance

Drug Misuse

A medicine can be beneficial when used correctly but harmful when misused.

Students should understand that medicines should be taken according to appropriate professional advice and product instructions.

Antimicrobial Resistance

When microorganisms become resistant to medicines designed to control them, treatment can become more difficult.

This is an important example of how human behaviour can affect both health and society.

9. CHEMISTRY AND FOOD

Chemistry is also involved in the food we eat.

Food chemistry helps us understand:

• Nutrients

• Food preservation

• Food additives

• Flavours

• Colours

• Food spoilage

• Food adulteration

Food Additives

Some additives are used for purposes such as:

• Preservation

• Improving flavour

• Maintaining texture

• Improving appearance

However, food additives should be properly assessed and used within appropriate safety requirements.

Food Adulteration

Food adulteration occurs when a food product is deliberately altered or contaminated in a way that reduces its quality or may make it unsafe.

This raises both ethical and legal issues because consumers have a right to safe and properly represented products.

10. CHEMICAL INDUSTRIES AND SOCIETY

Chemical industries are important to modern society.

They produce materials such as:

• Paints

• Soaps and detergents

• Fertilizers

• Plastics

• Medicines

• Fuels

• Construction materials

• Textile chemicals

They also create employment and contribute to economic development.

But industries have responsibilities.

A responsible chemical industry should consider:

Workers

Are workers properly trained and protected?

Consumers

Are products properly labelled and safe when used as directed?

Environment

Is industrial waste being properly managed?

Community

Could the company's activities negatively affect people living nearby?

This is why industrial chemistry involves more than simply making a product.

11. LEGAL ISSUES IN CHEMISTRY

Ethics tells us what is responsible or morally right, while laws and regulations establish requirements that people and organizations are legally expected to follow.

Governments regulate certain chemicals and chemical activities because improper handling can harm people or the environment.

Regulations may concern:

• Manufacture

• Storage

• Transportation

• Labelling

• Sale

• Use

• Disposal

• Environmental discharge

Why Are Chemical Regulations Necessary?

They help to:

• Protect workers.

• Protect consumers.

• Reduce environmental pollution.

• Control hazardous substances.

• Improve chemical safety.

• Ensure appropriate information is provided.

Important Point

Legal and ethical responsibilities are related but not exactly the same.

A person may obey the minimum legal requirement but still need to think about whether their actions are responsible toward other people and the environment.

12. ETHICS IN SCIENTIFIC RESEARCH

Scientific research depends heavily on trust.

Imagine a scientist publishes a result that was never actually obtained.

Other scientists may use that false information in their own work. This can waste time, money and resources and may sometimes put people at risk.

Therefore, scientists should:

• Record observations honestly.

• Avoid falsifying data.

• Give credit to other people's work.

• Avoid plagiarism.

• Clearly acknowledge limitations.

• Protect research participants where applicable.

• Follow approved safety procedures.

Remember

Science progresses through evidence, and evidence depends on honesty.

13. CHEMISTRY, TECHNOLOGY AND SOCIETY

Scientific discoveries often produce new technologies.

Examples include:

• Plastics

• Batteries

• Solar cells

• Nanomaterials

• New medicines

• Water-treatment technologies

These technologies can improve our lives, but they can also create new questions.

For example:

Plastics

Plastics are cheap, light and useful. They are found in packaging, medical equipment, construction and many other products.

But poorly managed plastic waste can persist in the environment and contribute to pollution.

So society has to consider:

How can we enjoy the benefits of plastics while reducing their environmental impact?

This is an example of a social issue connected to chemistry.

14. GREEN CHEMISTRY

One of the most important modern ideas in chemistry is green chemistry.

Meaning

Green chemistry involves designing chemical products and processes in ways that reduce or eliminate the use and generation of hazardous substances.

Instead of asking:

"How do we clean up all this waste after producing it?"

green chemistry encourages us to ask:

"How can we prevent the waste from being produced in the first place?"

Green Chemistry Encourages

• Prevention of waste

• Safer chemical processes

• Safer products

• Efficient use of raw materials

• Lower energy consumption

• Recycling and recovery

• Use of renewable resources where appropriate

• Reduction of hazardous substances

Simple Example

If two manufacturing methods produce the same useful product, but one method uses less hazardous material and produces less waste, the cleaner method is generally preferable.

15. CHEMISTRY AND SUSTAINABLE DEVELOPMENT

Sustainable development means meeting the needs of people today while protecting resources and the environment for future generations.

Chemistry can contribute through:

• Cleaner water-treatment methods

• Renewable-energy technologies

• Better batteries

• Environmentally safer materials

• Efficient agricultural chemicals

• Waste reduction

• Cleaner industrial processes

• Recycling technologies

In Conclusion 

The chemist of the future must therefore think beyond the laboratory.

A good question is:

"What effect will this chemical process have on people and the environment—not only today, but years from now?"

Chemistry gives us tremendous power to change the world.

We can use chemistry to produce medicines, clean water, improve agriculture, manufacture useful materials and develop new technologies.

But with that power comes responsibility.

Whenever you work with a chemical, ask yourself:

Is it safe?

Am I using it responsibly?

Am I obeying the relevant rules?

Could my actions harm another person or the environment?

That is the real meaning of Ethical, Legal and Social Issues in Chemistry.

Remember:

A good chemist does not only ask, "Can we do it?" A responsible chemist also asks, "Should we do it, and how can we do it safely?"

QUICK CHECK — TEST YOURSELF

1. What do we mean by ethics in chemistry?

2. Why is proper labelling of chemicals important?

3. Mention three ways chemical waste can harm the environment.

4. What is eutrophication?

5. State three examples of greenhouse gases.

6. Mention two benefits and two possible problems associated with pesticides.

7. Why are medicines tested before they are approved for use?

8. What is food adulteration?

9. Why do governments regulate hazardous chemicals?

10. What is green chemistry?

11. State four responsibilities of a chemical manufacturer.

12. Why is honesty important in scientific research?

OBJECTIVE QUESTIONS

1. A scientist changes experimental results to agree with the expected result. This is an example of

A. recycling
B. scientific honesty
C. scientific misconduct
D. green chemistry

2. Which of the following is the most responsible way of handling chemical waste?

A. Pouring it into a nearby river
B. Dumping it in an open field
C. Following an appropriate waste-management procedure
D. Mixing all wastes together

3. Excess nutrients entering a lake may cause

A. distillation
B. eutrophication
C. sublimation
D. neutralization

4. Which of the following is a greenhouse gas?

A. Nitrogen
B. Oxygen
C. Carbon dioxide
D. Argon

5. The main aim of green chemistry is to

A. increase chemical waste
B. prevent or reduce chemical hazards and waste
C. stop the use of chemicals
D. increase pollution

6. Which of the following is an example of an ethical responsibility?

A. Falsifying results
B. Hiding known hazards
C. Reporting results honestly
D. Dumping industrial waste into a river

7. A substance used to control unwanted insects on crops is called

A. fertilizer
B. insecticide
C. catalyst
D. solvent

8. Which of the following is a renewable source of energy?

A. Coal
B. Petroleum
C. Natural gas
D. Solar energy

9. Chemical regulations are mainly established to

A. prevent all chemical research
B. protect people and the environment
C. stop industrial development
D. prevent the use of laboratory chemicals

10. Which of the following best describes sustainable chemistry?

A. Producing chemicals without considering waste
B. Using chemistry in ways that consider long-term environmental and social impacts
C. Using the largest possible quantity of chemicals
D. Avoiding all chemical processes

THEORY QUESTIONS

1.(a) Explain what is meant by ethical responsibility in chemistry.

(b) State five ethical responsibilities of a chemist.

2. (a) What is environmental pollution?

(b) Mention three types of environmental pollution.

(c) State two ways of reducing chemical pollution.

3. Explain five reasons why chemical industries should be properly regulated.

4. What is green chemistry? State five advantages of practising green chemistry.