Chemistry is one of the ancient and main disciplines of
sciences. Various kinds of changes such as formation, destruction's, growth,
transformation, production etc. are discussed in chemistry. The practice of
chemistry has been continuing for a number of millennial. The process of
beautifying clothes by applying dyes was on track in the Indian sub continent
about 5000 years ago. Men started making metallic weapons, columns and statues
quite a long ago. In ancient times, precious metals like gold, silver, lead
etc. were extracted from mines using chemical technologies. Gold was extracted
by the Egyptians during 2600 B.C that is adored as a classy and precious metal
till today. The practice of chemistry during the ancient and Middle Ages is
known as Al-chemy. The word Al-chemy takes its origin from the Arabic word
Al-chimia which would signify the Egyptian civilization. The Ancient Egyptian
civilization became capable of meeting the needs of its people to a great
extent through the practices of chemistry. Now a day, in mills and industries,
the manufacturing of many consumer products starting from oil, sugar, paper,
pen, medicine, cloth, shampoo, soap, rod-cement etc. is done through the use of
chemistry. What is interesting is, present time chemistry is not confined only
within the activities of industries and testing or research laboratories. If we
observe the incidents happening around us, we will see the presence of
chemistry everywhere. Some events are cited in table-1 for example.
Table-1: Presence of chemistry
Subject
|
Analysis
|
Mango becomes
yellow as it ripens
|
Color is a chemical substance. The change in the color of mango to
yellow means the creation of yellow colored new compound in the mango
through biochemical process.
|
Rust in iron
|
Iron is hard, rust is fragile. Pure iron in presence of moisture reacts
with oxygen of air and form a substance named iron oxide, which is generally known
as rust.
|
Burning of wood,
kerosene, natural
gas or candle
|
These substances are mainly made of carbon compound. For example,
wood is mostly cellulose, natural gas is methane and wax is a compound of
carbon and hydrogen. Burning these substances means the burning of carbon
compound, which is a kind of chemical reaction that results in the production
of carbon dioxide gas, water vapor and heat.
|
So it can easily be assumed that, chemistry is somehow
related to the different changes happening in our environment. The acts of
making differences in the tastes of food through cooking may be called a kind
of chemistry. In fact, from the ancient civilization to modern age, the immense
journey of chemistry is observed in the society, that is, in almost all fields
of science.
Concepts of Chemistry
Chemistry is one of the diverse branches of physical
science. It is known as the science for life. The practice of chemistry has
been in constant increase since the ancient time. The present day chemical
industries have been evolved from the early practices of the Alchemists.
Chemistry as a discipline encompasses a wide range of areas. It has always been
devoted to the welfare of human and its environment. Therefore, in this age of
information technology, it is necessary for all to know where and with which
processes chemistry is involved in so that we can be benefited from applying
the knowledge in our daily life.
Scope of chemistry
The scope of chemistry is enormous, which is devoted to
serve to human race. The practice of chemistry is increasing with the pace of
time. Let us consider the use of chemistry in our life. You have got up from
bed with a heavy breathing and after brushing teeth, washed your hands and
faces with water. Then, you have sat in front of your table to study after
massaging an oily substance in your hands and mouth and combing your hair with
a comb. Opening the red covered book you have seen the writings on white paper
with black ink – chemistry is present in all these. After studying for some
time, you wrote the answers to some questions in your exercise book with a pen
or pencil. After that you had your food, and started for school wearing a white
shirt and a blue pant. On your way to school, you saw a farmer using fertilizer
in his garden or field. You also noticed a motor cycle running past you with
emitting smokes. Chemistry is also present in all these incidents. Now consider
the presence of chemistry in the usable things shown in Table-2. Table-2
Example of thinking about the scope of chemistry.
Substance
|
Element
|
Source
|
Air taken by inhalation
|
Mostly oxygen
|
Environment, air.
|
Brush, comb, artificial color, paper, exercise book, ink, pencil, pen
|
Made by the combination of different chemical compounds
|
Made in industries through the chemical changes of different
materials
|
Drinking water
|
Pure water is made of hydrogen and oxygen atoms. There are other
minerals too in drinking water.
|
Water exists in nature, e.g. river, drain, canal, bill, ocean, rain,
water fall etc.
|
Food
|
Starch, protein, fat all are organic compounds and different mineral substances.
|
Plants (by photosynthesis) and animals produce and deposit foods by
different process. When we take food, metabolic process occurs in our bodies
and we get energy.
|
Shirt and pant
|
They are made from the combination of organic compounds and fibers.
|
Clothes are made in textiles and fabrics industries by combining dyes
with natural or synthetic fibers made of different compounds through chemical
reactions.
|
Fertilizer
|
These are made of oxygen, nitrogen, carbon, phosphorus etc. and
combination of different chemical compounds.
|
Fertilizers are manufactured in industries by chemical reactions.
Chemical fertilizers supply nutrients the soils with nutrients for the
plants.
|
Motor cycle and its
energy to move
|
It is made by the combination of different parts made of various
metals and plastics. A motorcycle gains the energy to run by combustion of
petroleum.
|
Metals are extracted from the minerals using chemical methods.
Plastics are also made in industries by chemical reactions. Combustion of
petroleum is a chemical process.
|
Relation of chemistry with the other brunches of Science
We have learned that chemistry is one of the main branches
of science. There is a particular relation of chemistry with the other branches
of science like mathematics, physics, zoology, environmental science,
geological science etc. In fact, as the other branches of science are dependent
on chemistry, similarly, the explanations and theoretical concepts of many
events of chemistry are given with the help of other sciences.
You have read in life cycle that, directly or indirectly,
plants serve as the source of foods for all animals. Plants deposit foods in
different ways by a bio-chemical process called photosynthesis. Again animal
body is made of different complex molecules such as protein, fat, compounds of
calcium, DNA etc. the birth and growth of animal function through a
bio-chemical process, which is a subject of biology.
In modern time, features well-known as the contribution of
science like electricity, magnet, computer and theory of different electronic
production and uses are discussed in physics. If we observe, we can see that
all these materials are produced by the combination of different chemical
properties of matters. The production and distribution of electricity may be
considered here for example. Electricity is produced from the combustion of
oil, gas, and coal, that is, from the heat generated through chemical reactions
and distributed by the flow of electrons of metallic wire (e.g. copper).
Various small parts of computer and other electronic goods like- CD, memory
disk, monitor are produced by the combination of chemical properties of different
matters. On the other hand, it is said that, the amount of copper that is
already used in production of computer and other electronic goods is greater
than the amount is still stored unused in nature. If copper is being used in
this rate, one day it will be finished. Besides, the amount of such unusable
goods will increase day by day and will cause harm to our environment. So it is
necessary to recycle copper from those goods and to reuse. It can also be done
by practicing chemistry.
On the other hand, plant and animal bodies get rotten after
death and mix with soil through various microbial processes. Due to the
absorbed heat and pressure of earth the materials which mix with soil undergo
more chemical changes. As a result, they are converted to different minerals
such as, petroleum; coal, natural gas etc. In atmospheric science
identification of the ozone layer and ozone layer depleting gases are performed
by different process of chemistry.
Now the dependency of chemistry on the other sciences can be
considered. It is impossible to present the theories of chemistry or to acquire
the theoretical knowledge of chemistry without mathematics. Calculations in
chemistry, derivation of a rule and mathematical relations all are mathematics.
Quantum mechanics is, in fact, mathematical calculations to explain the atomic
structure. On the other hand, different experiments in chemistry are instrument
dependent. The principles of these instruments or experimental principles are
established on the basis of physics. From the above discussion it is understood
that, there is a strong relation between chemistry and the different branches of
science.
Importance of learning chemistry
We have understood from our reading of the scope of
chemistry that, chemistry is always involved in providing basic human needs
like- food, clothing, housing, medication and material of education. It is
worth mentioning here that, the belief held by people of different sectors of
the society that chemical substance means something hazardous, it is not
correct.
Whatever we are eating, such as, rice, pulses, oil, sugar,
salt and what we are using like soap, shampoo, detergent powder, medicine etc.
are all chemical substances. Aren’t they?
The fertilizers and insecticides used in agriculture are all
chemical substance. Insects are prevented from destroying the crops by using
insecticides. We are using coil or aerosol to prevent mosquitoes. Soaps,
shampoo, detergents are used in cleaning. We take medicines, antibiotics and
vitamins to maintain our health. Various types of natural substances like
turmeric, henna and artificial cosmetics and colors are used in beautification.
In addition to that we are taking various types of herbal medicines and other
materials to protect our health and for beautification. Sometimes inexperienced
and dishonest people or farms produce and distribute these materials. Banned
chemicals are being used unconsciously or dishonestly to prevent fish and meat
from being rotten and to get fruit ripen quickly without considering the damage
they cause to human health. Similarly illegal and non-food graded dyes are
being using to make foods attractive.
To preserve processed foods for a long time preservatives
are used specially in juice, sauce, cake, biscuit etc. Processed food without
preservative may be harmful for life, but unfortunately, in most cases, in
processing these foods excess amounts of forbidden and non food graded
preservatives are uses.
On the other hand the heat used in burner for cooking is
created by burning of wood or natural gas, where heat, carbon dioxide and other
substance are produced from the reaction of oxygen in the air, wood or natural
gas. It is worth mentioning that if wood and natural gas is burnt in presence
of insufficient air, a gas called carbon-mono-oxide, which is very harmful for
human health may be produced. Besides, on burning of wood or coal harmful
carbon particles are produced, we call it soot (Kali), when they settle on the
wall of the container. In the same way carbon dioxide gas is being produced
from industries and automobile engines, which is very harmful to the
environment.
Excess fertilizer, pesticide, soap, detergent, shampoo, etc.
are polluting the soil and water of rivers and canals. We take the smoke of
mosquito coil and aerosols with our inhalation. We use the artificial
cosmetics, colors and herbals which reach to the different parts of our body
with blood circulation. On the other hand, the produced carbon dioxide on
production of heat or energy go to air and contribute to the increase of the
temperature in our atmosphere.
We know, excess use of chemical fertilizer causes harm to
the plants even may cause them to die. Similarly carbon-mono-oxide gas which is
very harmful for human is produced on burning of wood or coal with limited
supply of air. Excess doses of medicines may even cause people to die.
Therefore, it is clear that for good results, the recommended uses of chemical
substances are necessary and that can be ensured only by thorough understanding
of chemistry. On the other hand, one can be aware of the risk factors and
hazards of various chemical substances from studying chemistry which can build
up us as conscious citizens. Along with this we, the users and manufacturers of
various products can play important roles in protecting our society and
environment by ensuring the proper uses of such products through quality
assessment. Therefore, it is clear that, it is very important for everyone to
have some knowledge of chemistry.
End
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