The Importance of Learning Chemistry

1.0Introduction to Science

What is science? Is it a list of marvelous inventions and how they work? Or is it a list of theories about matter and energy and biological systems? Or is science a subject that you learn by carrying out activities in a laboratory? Science is all of these, but it is also something even more basic. 

Science is a method of thinking that allows us to discover how the world around us works.

The word science comes from the Latin word "Scientia," meaning knowledge. Science and technology can make lives healthier, more convenient, and safer.

2.0Branches of Science

The three main branches of science

Science, in the broadest sense, can be viewed as an attempt to organize and understand our observations of nature. Because this is a vast undertaking, science is subdivided into various disciplines, including chemistry, biology, geology, and physics.

(1) Life science : Study of living systems and the ways in which they interact.

(2) Earth science : Study of Earth systems and the systems in space. 

(3) Physical science : Study of non-living things.

Physical science is further divided into

(i) Physics: Physics is the study of the natural world. It deals with the fundamental particles of which the universe is made and the interactions between those particles, the objects composed of them (nuclei, atoms, molecules, etc.) and energy.

(ii) Chemistry: Chemistry deals with the properties of matter and the transformation and interactions of matter and energy. Chemistry is about the interaction of one substance with another, such as in a chemical reaction, where a substance or substances are transformed into another.

3.0Some Important Terms

Matter: Matter is the general term for the material things around us we can define it as whatever occupies space and have volume or can be perceived by our senses. 

Eg. → Pen, Book, water, air etc.

Atom: The smallest particle of a chemical element that can exist. For example, C, O, N, H, etc.

Molecule: Molecules made up of one or more atoms. For example, H₂, N₂, O₂, etc.

Element: It is defined as a substance that cannot be further divided to simpler substances by ordinary processes. For example, C, O, N, H, etc.

Compound: A compound is formed by combination of two or more elements in a definite proportion. For example, H₂O, CO₂, etc.

Mass: Mass is the quantity of matter in a physical body.

Density: Density is the mass per unit of volume of any substance.

Volume: Volume is a measure of occupied three-dimensional space.

4.0Macroscopic and microscopic world

As we proceed, you will see how the concepts of chemistry allow us to understand the nature of changes. Chemists “look inside” ordinary objects to observe how the fundamental components are behaving.

We are now in the microscopic world, but as chemists, we wants to go even further. What are the building blocks of the cells and what are the components of the water that contains the dissolved nutrients?

Think about water, a very familiar substance. In the macroscopic world, it flows and splashes over rocks in mountain streams and freezes on ponds in the winter.

5.0What is Chemistry? 

To put it simply, chemistry is a science that deals with how materials form, their composition, various attributes, how they transform, and the energy they consume or release through these transformations. 

Chemistry relates to each and everything you can sense, from right down to the elemental level to massive complex structures. 

It deals with how things are constructed and formulated to how they break apart and the energy that is either absorbed or released in each of these processes. The study of the science of chemistry shows us for example, how the table salt we eat everyday is actually constructed or crystals formed out of sodium and chlorine, and why the Statue of Liberty, constructed out of metallic copper, is green.

Chemists are people who understand, deal with and use chemistry in three distinct ways

(i) They help to explain occurrences, describing how things occur and why they occur.

(ii) They investigate materials to study and discover their chemical composition.

(iii) They combine and blend substances to create new chemicals and compounds such as medication and shampoo.  

6.0History of Chemistry

Chemistry had its beginnings in China in the 3^rd century BC. Its progress, however, was slow as there was no proper explanation of all the observed changes. One idea was the assumption that anything could be changed into anything else. Those trying to put such an idea into practice were called alchemists. 

7.0What is Alchemy?

Alchemy was one of the earliest forms of chemistry. It combined science, magic, philosophy, and religion. Alchemists are the forerunners of present-day chemists. They were perhaps the earliest experimentalists. Alchemists cloaked their work in mystery and mysticism. They had secrets to keep because they thought they could change cheap metals like lead into gold and so get rich quickly. Their use of secret codes and symbols translated to the modern representation of elements by symbols and chemical reactions by equations (the so-called ‘language of chemistry’).

Not until less than 250 years ago were true foundations of chemistry laid – the nature of air and water was discovered. Water was shown to be a compound of hydrogen and oxygen, whereas air was shown to be a mixture of several gases. In the 20^th century, important discoveries related to the structure of the atom were made. From these discoveries, chemists have worked out how and why elements combine together to form compounds. But it is through the conquest of materials and the making of new substances that the chemist continues to make a mark on society.

8.0Why Study Chemistry ?

Chemistry is in everything that you see, smell or touch. Your own body is  a complex chemical factory! Understanding chemistry helps you to understand the world around you. Cooking is chemistry. Everything you can touch or taste or smell is a chemical. When you study chemistry, you come to understand a bit about how things work. Chemistry isn't secret knowledge, useless to anyone but a scientist. It's the explanation of everyday things, like why laundry detergent works better in hot water or how baking soda works or why not all pain relievers work equally well on a headache. If you know some chemistry, you can make educated choices about everyday products that you use.

9.0Some branches of Chemistry

Organic Chemistry

Organic chemistry is the branch of chemistry that involves the scientific study of organic compounds. The study of substances containing carbon.  This branch of chemistry primarily deals with the structure and chemical composition of organic compounds, the physical and chemical properties of organic compounds, and the chemical reactions undergone by these compounds. 

Inorganic Chemistry

The study of substances not containing carbon. In simple words, it is opposite to that of Organic Chemistry. The substances which do not have carbon-hydrogen bonding are metals, salts, chemical substances, etc.

Analytical Chemistry

Analytical chemistry is the branch of chemistry that deals with the analysis of different substances. Analytical chemistry involves the separation, identification, and the quantification of matter. It involves the use of classical methods along with modern methods involving the use of scientific instruments.

Physical Chemistry

The study of physical properties related to chemistry. It also involves the study of the properties of substances at different scales, from the macroscopic scale which includes particles that are visible to the naked eye, to the subatomic scale involving extremely small subatomic particles such as electrons.

Biochemistry

The branch of science dealing with the study of all the life processes such as control and coordination within a living organism is called Biochemistry. The study of chemical make-up and behaviour in living things.

For some, chemistry has a reputation of being a complicated and boring science, but for the most part, that reputation is undeserved. It is rather very interesting. 

Fireworks and explosions are based on chemistry, you know the big-name brands that sell perfumes, or the shampoo you use, or the soap, the dish washing liquid, toothbrush or toothpaste all of these are formulated by chemists. 

In chemistry classes, you apply math and logic, which can make studying chemistry a challenge.

However, anyone can understand the basics of how things work and that's the study of chemistry. In a nutshell, the importance of chemistry is that it explains the world around you.

10.0Chemistry Explains

Cooking

Chemistry explains how food changes as you cook it, how it rots, how to preserve food, how your body uses the food you eat and how ingredients interact to make food.

Cleaning

Chemistry explains how cleaning works. You use chemistry to help decide which cleaner is best for dishes, laundry, yourself and your home. You use chemistry when you use bleaches and disinfectants and even ordinary soap and water. How do they work? That's chemistry!

Medicine

You need to understand basic chemistry so you can understand how vitamins, supplements and drugs can help or harm you. Part of the importance of chemistry lies in developing and testing new medical treatments and medicines.

Antoine Lavoisier is considered as the 'Father of Chemistry'.

Environmental Issues

Chemistry is at the heart of environmental issues. What makes one chemical a nutrient and another chemical a pollutant? How can you clean up the environment? Which processes can produce the things you need without harming the environment?

However, the knowledge of chemistry can also be misused to create dangerous explosives and chemical weapons that can cause massive destruction.

11.0Notable Personalities

(i) Robert Boyle (1627-1691) gave the earliest idea about elements and proposed that an element is a pure substance that cannot be split into anything simpler.

(ii) Antoine Lavoisier (1743-1794) classified elements as metals and non-metals. He is also called the ‘father of chemistry’.

(iii) Joseph Priestely (1733-1804) discovered oxygen.

(iv) Henry Cavendish (1731-1810) discovered hydrogen.

(v) John Dalton (1766-1844) proposed the atomic theory.

(vi) Michael Faraday (1791-1867) laid the foundation of modern-day electrochemistry. 

(vii) J.J. Thomson (1856-1940) discovered electrons.

(viii) Ernest Rutherford (1871-1937) put forward the model of an atom.

(ix) Niels Bohr (1885-1962) received the Nobel prize in 1922 for his contributions to the understanding of atomic structure and quantum mechanics. 

12.0Scientific Method

Experiment – An experiment is an observation of natural phenomena carried out in a controlled manner so that the results can be duplicated and rational conclusions obtained.

Law – A law is a concise statement or mathematical equation about a fundamental relationship or regularly of nature.

Hypothesis – A hypothesis is a tentative explanation of some regularity of nature.

Theory – A theory is a tested explanation of basic natural phenomena.

A representation of the scientific method to prepare the vaccine for COVID-19

Observation of Natural Phenomena

Fever, Cough, shortness of breath, body ache, Headache, low, oxygen level. (symptoms similar to viral infections)

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Hypothesis 

Viral vaccination can induce are immune response to fight against the virus.

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Testing (Further Experiments)

Vaccines teach our immune system to recognize an infection more quickly, allowing us to start fighting the virus before it multiplies, volunteers were being injecting with vaccine by introducing either dead or weakened virus, then they were kept in careful observation for some period of time then antibodies are developed.

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Positive Results 

If the real virus enters your body the antibodies that our immune system is already producing will know to attack if immediately then it is need to be generalized to the large population to judge its effectiveness. (younger at low risk or older at high risk).

13.0Common Laboratory Apparatus

Beaker

It is a cylindrical vessel with a flat bottom and pouring tip. The beaker is used for mixing, storing and heating substances. 

Flask

It is a glass bottle with a narrow neck and broad base.

Round bottom flask, Flat bottom flask, Conical flask

Measuring Cylinder

It is a graduated glass cylinder, available in different capacities, such as 100, 500 and 1000 mL. It is used for measuring the volume of liquids.

Volumetric Flask

A Volumetric Flask is a pear-shaped lab apparatus with a round flat bottom commonly used for dilutions and preparing standard solutions. The volumetric flask, also known as measuring flask or graduated flask, is lightweight, compact, and chemical resistant. The flask has ring graduation marking on its extended neck, which stipulates the liquid volume. 

Funnel

It is a cone-shaped wide glass vessel drawn into a narrow neck. It is used in filtration and for transferring liquids to containers. It prevents the spilling of the liquid being poured.

Gas Jar 

It is used to collect and store gases.

Fig. 5(a) Funnel  (b) Gas jar 

Test Tube

They are used to perform chemical tests.

Hard Glass Tube 

It is used for heating substances at high temperatures. Therefore, it is also called a boiling tube.

Iron Stand

It is used to suspend and hold apparatus.

Tripod Stand 

It is used for keeping glassware like beaker, flask, etc., for heating.

Wire Gauze

It ensures uniform distribution of heat.

Test Tube Stand

Made of wood or plastic, a test tube stand is used for supporting test tubes.

Test Tube Holder

It is used for holding the test tube while it is being heated.

Test Tube Brush 

It is used to clean test tubes and other glassware, such as flasks.

Porcelain Dish

It is an open and shallow container made of porcelain. It is used for evaporating liquids or concentrating solutions. It can absorb a large amount of heat without breaking.

Watch Glass

It is a saucer shaped small glass vessel used for holding small quantities of solutions or water or powdered substances for observation.

(a) Porcelain dish (b) Watch glass 

Mortar and Pestle

Solid substance are ground into powder in a mortar with the help of a pestle. 

Spirit Lamp

It has a neck through which a cotton wick passes. The wick soaks up the spirit and burns when lighted. It is used for heating.

(a) Spirit lamp (b) Bunsen burner

Bunsen Burner 

It is a burner which uses gas as a fuel to produce the flame.

14.0Precautions to Be Taken in A Chemistry Laboratory

Precautions

(1) It is advisable to wear a laboratory coat or an apron to protect the clothing.

(2) Never taste a chemical or inhale extensively its vapours until you are asked to do so by your teacher.

(3) When a chemical is not in use, its container should be closed tightly to prevent if from spilling or its vapours diffusing in air to cause irritation.

(4) If a chemical reagent gets into your eyes or mouth or on the skin, wash the affected areas immediately with water and report the incident to your teacher or laboratory incharge.

(5) In order to neutralise acid spills on the clothing or skin, use a very dilute ammonia or sodium bicarbonate solution. 

(6) Keep flammable chemicals like alcohol, acetone, etc., away from the burner.

(7) Never add water to a concentrated acid like sulphuric acid. Such an addition generates a lot of heat which may break the glass container causing a dangerous spill. Always add acid to water slowly, stirring continuously.

(8) Never throw a burning matchstick or a burning paper into a sink where it may ignite a discarded flammable liquid.

(9) You are required to take extra precautions while heating a chemical or mixture in a glass container. Some of these precautions are briefly described below :

Some Advised Precautions

To heat a chemical substance in a test tube, apply the flame at the upper layer of the liquid as shown in the figure. Never apply the flame at the bottom of the test tube as it may cause the liquid to boil over. Moreover, the test tube should first be heated gently and then strongly at the outer part of the flame, with continuous shaking.

(a) Right method of heating a test tube (b) Wrong method of heating a test tube

While heating the contents of a test tube be sure to point the open end of the tube away from your classmates and yourself as shown in the figure. 

(a) Right method of holding test tube while heating

(b) Right method of heating the contents of a flask

(10) Chemicals can be absorbed through the skin. Thus, it is a good habit to wash your hands immediately after they come in contact with any chemical.

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