easykemistry

Sunday, 27 September 2026

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


Wednesday, 16 September 2026

Introduction to Chemistry at a glance.

Introduction to Chemistry 

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.

  1. (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.

  2. (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.



Thursday, 10 September 2026

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

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, NOโ‚“

  • 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.