What is Chemistry and How to Tame It?

Chemistry is the study of matter and its changes. This includes everything in the universe from a simple hydrogen atom to very large replicating molecules in life processes. Chemistry is involved with the development of medicines that control and cure diseases; food production through specific and safe agricultural chemicals; consumer products such as cleaners, plastics and clothing; new methods of energy production, transfer and storage; new materials for electronic components; and new methods for protection and cleanup of the environment. Chemists are needed to help solve some of society’s most difficult technological problems through research, development and teaching.

A major branch of chemistry, known as ‘Inorganic Chemistry’, is generally considered to embrace all substances except hydrocarbons and their derivatives, or all substances that are not compounds of carbon (including some of the small molecules of carbon.) It covers a broad range of subjects, among which are atomic structure, crystallography, chemical bonding, coordination compounds, acid-base reactions, ceramics, and various  subdivisions of electrochemistry (electrolysis, battery science, corrosion, semi conduction, etc.). It is important to state that inorganic and organic chemistry often overlap. For example, chemical bonding applies to both disciplines, electrochemistry and acid-base reactions have their organic counterparts, catalysts and coordination compounds may be either organic or inorganic.

Regarding the importance of inorganic chemistry, R.T. Sanderson has written: “All chemistry is the science of atoms, involving an understanding of why they possess certain characteristic qualities and why these qualities dictate the behavior of atoms when they come together. All properties of material substances are the inevitable result of the kind of atoms and the manner in which they are attached and assembled. All chemical change involves a rearrangement of atoms. Inorganic chemistry (is) the only discipline within the chemistry that examines specifically the differences among all the different kinds of atoms”.

Another major branch of chemistry is ‘Organic Chemistry’ which embraces all compounds of carbon except such binary compounds as the carbon oxides, the carbides, carbon disulfide, etc.; such ternary compounds as the metallic cyanides, metallic carbonyls, phosgene (COCl2), carbonyl sulfide (COS), etc.; and the metallic carbonates, such as calcium carbonate and sodium carbonate. The total number of organic compounds is indeterminate, but a huge number has been identified and named. Important areas of organic chemistry include polymerization, hydrogenation, Isomerisation, fermentation, photochemistry, and stereochemistry. There is no sharp dividing line between organic and inorganic chemistry, for the two often tend to overlap.

Application of the concepts and laws of physics to chemical phenomena is included under the heading ‘Physical Chemistry’ in order to describe in quantitative (mathematical) terms a vast amount of qualitative (observational) information. A selection of only the most important concepts of physical chemistry would include: the electron wave equation and the quantum mechanical interpretation of atomic and molecular structure, the study of the subatomic fundamental particles of matter, application of thermodynamics to heats of formation of compounds and the heats of chemical reaction, the theory of rate processes and chemical equilibria, orbital theory and chemical bonding, surface chemistry, including catalysis and finely divided particles, the principles of electrochemistry and ionization. Although physical chemistry is closely related to both inorganic and organic chemistry, it is considered a separate discipline.

Analytical Chemistry is the subdivision of chemistry concerned with identification of materials (qualitative analysis) and with determination of the percentage composition of mixtures or the constituents of a pure compound (quantitative analysis). The gravimetric and volumetric (or “wet”) methods (precipitation, titration and solvent extraction) are still used for routine work and new titration methods have been introduced e.g. cryoscopic, pressure-metric (for reactions that produce a gaseous product), redox methods, and use of a F-sensitive electrode etc. However, faster and more accurate techniques (collectively called instrumental) have been developed in the recent past. Among these are infrared, ultraviolet, and x-ray spectroscopy where the presence and amount of a metallic element is indicated by lines in it’s emission or absorption spectrum; colorimetry by which the percentage of a substance in soluble is determined by the intensity of it’s colour; chromatography of various types by which the components of a liquid or gaseous mixture are determined by passing it through a column of porous material or on thin layers of finely divided solids; and separation of mixtures in ion exchange columns and radioactive tracer analysis. Optical and electron microscopy, mass spectrometry, microanalysis, Nuclear Magnetic Resonance (NMR) and Nuclear Quadrupole Resonance (NQR) spectroscopy all fall within the area of analytical chemistry. New and highly sophisticated techniques have been introduced in recent years, in many cases replacing traditional methods.

Originally Biochemistry was a subdivision of chemistry but now an independent science, which includes all aspects of chemistry that apply to living organisms. Thus, photochemistry is directly involved with photosynthesis and physical chemistry with osmosis, two phenomena that underline all plant and animal life. Other important chemical mechanisms that apply directly to living organisms are catalysis, which takes place in biochemical systems by the agency of enzymes; nucleic acid and protein constitution and behavior, which is known to control the mechanism of genetics; colloid chemistry, which deals in part with the nature of cell walls, muscles, collagen, etc; acid-base relations, involved in the pH of body fluids; and such nutritional components as amino acids, fats, carbohydrates, minerals, lipids and vitamins, all of which are essential to life. The chemical organization and reproductive behavior of microorganisms (bacteria and viruses) and a large part of agricultural chemistry are also included in biochemistry. Particularly active areas of biochemistry are nucleic acids, cell surfaces (membranes), enzymology, peptide hormones, molecular biology, and recombinant DNA.

Nuclear Chemistry is the division of chemistry dealing with changes in or transformations of the atomic nucleus. It includes spontaneous and induced radioactivity, the fission or splitting of nuclei, and their fusion, or union; also the properties and behavior of the reaction products and their separation and analysis. The reactions involving nuclei are usually accompanied by large energy changes, far greater than those of chemical reactions; that are carried out in nuclear reactors for electric power production and manufacture of radioactive isotopes for medical use, also (in research work) in cyclotrons.

Stoichiometry is the branch of chemistry and chemical engineering that deals with the quantities of substances that enter into, and are produced by, chemical reactions.  Stoichiometry provides the quantitative relationship between reactants and products in a chemical reaction. For example, when methane unites with oxygen in complete combustion, 16g of methane require 64g of oxygen.  At the same time 44g of carbon dioxide and 36g of water are formed as reaction productions. Every chemical reaction has its characteristic proportions.  The method of obtaining these from chemical formulas, equations, atomic weights and molecular weights, and determination of what and how much is used and produced in chemical processes, is the major concern of Stoichiometry.

Many students treat chemistry as “too difficult to understand and prefer to escape and memorize even on the expense of the realization that by doing so they are bound to harm themselves now and deprive the society of their contribution later. Henceforth they should note that although it is somewhat challenging, any reasonably intelligent and dedicated student can succeed in chemistry. They should also realize that there is no use of wasting both money and time for some thing that is either memorized before examination or forgotten thereafter or some portion of it is dropped under the pretext of selection of important topics for the purpose of preparation for examination. One must not waste his/her valuables (money and time) just for the sake of degree and literacy as both of these are bound to have detrimental consequences not only for the individual concerned but also the society for obvious reasons.

Those of the students who get their confidence shattered whenever they come across chemistry may note Some Tips (given below) from tose who have succeeded in Chemistry

Develop good study habits. Attend all lectures and labs. Take all lecture notes and make your own notes after understanding things properly. Use your lecture notes as a guide to your reading in the textbook. Write your questions down if you don’t understand something. Ask your teacher if you don’t understand a concept. Make flash cards of definitions, concepts, reactions, structures, and nomenclature that are in the textbook and are emphasized by your teacher in lecture. Remember that writing something is equivalent to reading it ten times and notes are records for recollecting the material and not something to be memorized in a capsule form. Do all the homework problems sincerely and with sincerity. One of the best ways of learning is to find a study partner or to form a study group and work on problems independently and then together. Keep yourself up –to- date. If you get behind or get a poor grade in class tests, either you want to drop the class or may be made to drop the class. Try to see the ‘big picture; of the future instead of being mean and escapist. Practice applying what you have learned in class to the world around you. Try to foster your own scientific curiosity and wonder around ‘why things are and how they happen’. Have a positive attitude. Realize that science requires more self discipline, but offers more rewards. Try to be organized and recognized. Persevere and be determined to succeed.

Dr.Badruddin Khan teaches Chemistry in the University of Kashmir, Srinagar, India.

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