Frequently Asked Questions on Chemistry

 Frequently Asked Questions on Chemistry

Q1

What Is the Periodic Table?

The periodic table of chemical elements, often called the periodic table, organizes all discovered chemical elements in rows (called periods) and columns (called groups) according to increasing atomic number. In 1869, Russian chemist Dmitri Mendeleev created the framework that became the modern periodic table, leaving gaps for elements that were yet to be discovered.

“Sulphuric acid” is called the king of acids and “Nitric acid” is called the Queen of acids.

Q2

What are the 3 laws of gas?

Boyle’s Law tells us that the volume of gas increases as the pressure decreases. Charles’ Law tells us that the volume of gas increases as the temperature increases. And Avogadro’s Law tell us that the volume of gas increases as the amount of gas increases.

“Sulphuric acid” is called the king of acids and “Nitric acid” is called the Queen of acids.

Q3

What is a chemical change? Is cooking an egg a chemical change?

There are changes all around us like sugar dissolves in water, the lake freezes in winter etc. Some changes are what scientists call chemical changes and some are not. A chemical change takes place when new substances are made that are different from the substances that we started with.

Yes Cooking eggs, for instance, is an example of a chemical change; the egg white and egg yolk change from liquid to solid. The heat makes the proteins in the egg hardens.

Q4

Which acid is called “Kingly Water” and why?

Aqua Regia is the King’s Water, this is because it is strong enough to dissolve gold – the king of metals. It is prepared by mixing three parts of hydrochloric acid with one part nitric acid but in olden days it is prepared to mix and distill salts. For example, we can mix two parts niter with one part Sal. Ammoniac and distill at a high temperature to form Aqua Regia.

“Sulphuric acid” is called the king of acids and “Nitric acid” is called the Queen of acids.

Q5

What are the main branches of chemistry?

Chemistry is the science that studies atoms and molecules along with their properties. All matter is composed of atoms and molecules. There are 5 main branches of chemistry are

• Organic chemistry
• Inorganic chemistry
• Physical chemistry
• Biochemistry
• Analytical chemistry

Q6

What is the importance of organic chemistry?

Organic chemistry is simply the study of carbon compounds. Organic chemistry is important because it is life studies and all life-related chemical reactions. Organic chemistry initially involves the study of compounds that could be obtained from living organisms.

Approximately 7 million different organic compounds are known present while there are only 1.5 million known inorganic compounds. This large number of organic compounds arise from the unique property of carbon.

Q7

Which compound is known as “Blue Vitriol”?

Blue vitriol is also known as blue copperas. The word blue vitriol has a strict and definite meaning. It means sulphate of copper with the chemical formula CuSO4.5H2O. The chemical name for blue vitriol is Copper (II) Sulphate Pentahydrate. This salt occurs in the form of rhomboidal prisms of a deep blue colour, having an exceedingly harsh and styptic taste.

Similarly, “Green Vitriol” refers to Ferrous Sulphate.

Relationship Between Chemistry and Other Branches of Science

 

Relationship Between Chemistry and Other Branches of Science

‘Science’ can be defined as the systematic study of the natural universe, its structure, and everything it encompasses. Due to the immensity of the natural universe, science has been divided into several disciplines that deal with certain aspects of the universe. The three primary subcategories of science under which these disciplines can be grouped are:

• The Formal Sciences: Involves the study of the language disciplines that concern formal systems. Examples of scientific disciplines that fall under this category include logic and mathematics. Can be thought of as the “language of science”.
• The Natural Sciences: Involves the study of natural phenomena through experiments and observations. Chemistry, physics, and biology fall under this category of science.
• The Social Sciences: Involves the study of human societies and the relationships between the humans that dwell in these societies. Examples of scientific disciplines that fall under this category include psychology, sociology, and economics.

When the relationships between the major branches of science are considered, chemistry is found to lie close to the centre (as illustrated below).

Thus, chemistry can be viewed as a central science whose roots bore into several other subdisciplines of science.

Branches of Chemistry

The five primary branches of chemistry are physical chemistry, organic chemistry, inorganic chemistry, analytical chemistry, and biochemistry. Follow the buttons provided below to learn more about each individual branch.

Organic Chemistry

 

Inorganic Chemistry

 

Physical Chemistry

 

Biochemistry

 

Analytical Chemistry

 

Chemistry Reactions

Apart from these primary branches, there exist several specialized fields of chemistry that deal with cross-disciplinary matters. Some such examples include medicinal chemistry, neurochemistry, materials chemistry, nuclear chemistry, environmental chemistry, polymer chemistry, and thermochemistry.

 

Nobel prize in chemistry awarded for work on mirror molecules

Henri Kagan and Kenso Soai have been honoured for their work on making molecules form the correct mirror images

By Carissa Wong

he 2026 Nobel prize in chemistry has been awarded to Henri Kagan and Kenso Soai for their discovery of how to make molecules form the correct kind of mirror image. This has enabled the molecules to be mass produced with chemical properties that are useful in various applications, such as medicines and agriculture.

Some molecules exist in two forms that are mirror images of each other, which chemists call right- and left-handed. “Like my hands, they are one another’s mirror image, they look alike but they are not identical,” Heiner Linke, chair of the Nobel committee for chemistry, said at a press conference. “Such molecules are called chiral from the Greek word for hand.” 

For decades, whenever chemists carried out chemical reactions, they produced two forms of mirrored molecules in equal proportions. But they only wanted to make one of the mirror images when producing molecules that would interact with life, like medicines, because only one would have the desired effect.

“Many active drugs in pharmaceutical applications are chiral: one hand may have the desired therapeutic effect, while the other hand might have no effect, or in the worst case might even be harmful,” said Linke.

 In 1986, Henri Kagan at Paris-Saclay University, France, discovered a way to tilt chemical reactions towards generating more of one mirror molecule over the other.

Taking this further, in 1995, Kenso Soai at the Tokyo University of Science, Japan, started designing chemical reactions to produce only one mirror image. In 2003, he achieved this. His “Soai reaction” gets one form of mirror molecule to amplify itself, in a process known as autocatalysis, so it makes up most of the reaction products.

 

Lab Safety Protocols

Cell phones and pagers may not be used while working in the undergraduate laboratories, to prevent any distractions from leading to mistakes or accidents.

Head phones and earbuds may not be used while working in lab, as it is important that you can hear someone yell "watch out" or otherwise get your attention.

Counter Tops in labs should remain clear of anything that is not required for the lab (laboratory equipment, lab manuals, lab notebooks, etc.). All personal belongings should be stowed in the designated area in the lab, or in the lockers provided on the second and third floors of Bagley Hall.

Laboratory Walkways should remain clear of any obstructions to avoid trips and falls, and to avoid accidental contamination. Please stow all belongings in the designated area in the lab, or in the lockers provided on the second and third floors of Bagley Hall.

Chairs and Stools may not be used while lab work is in session, unless required for a special accommodation. Chairs and stools are a trip hazard. You should plan to stand throughout the lab session, allowing you to move quickly in the event of fire, an explosion, or some other chemical mishap occurring on the bench in front of you.  

 

Student Lab Attire

Eye Protection

Eye protection must be worn at all times in the undergraduate laboratories. Splash goggles with splash proof sides are required eye protection in all undergraduate laboratories. Avoid use of contact lenses in the laboratory; if you wear contact lenses, notify the laboratory supervisor.

Lab Coats

The Dept of Chemistry highly recommends 100% cotton lab coats as they offer superior protection against flames and heat.  Contaminated personal clothing may spread hazards to family and friends, as well as contaminate public areas such as doors, hallways, elevators and food services. Everyone working in an undergraduate laboratory is required to wear laboratory coats at all times. The correct style of lab coat for undergraduate laboratories: button or snap in front; long to at least mid-thigh.

Shoes

Shoes with closed toes and backs are required for everyone working in an undergraduate laboratory. No shoes with cut-outs or vents that leave skin exposed and unprotected are allowed.

Clothing

Appropriate leg coverage by long pants without any tears or holes is required for everyone working in the undergraduate laboratories. Shorts, capri pants, or any other lower-body coverings that leave skin exposed or unprotected are not allowed. Also prohibited are nylon panty hose and tights. Skirts are appropriate if they are not too loose and are long enough to fully cover the leg.

All loose clothing should be confined to avoid easily catching fire, being dragged through chemicals, or becoming entangled in moving machinery. Clothing cannot drag on the floor.

It is recommended that anyone working in undergraduate laboratories remove jewelry to prevent collecting chemicals, contacting electrical sources, catching on laboratory equipment, and/or damage to the jewelry itself.

Gloves 

Use of gloves may be recommended, or even required, in the undergraduate laboratories based on the chemicals being used. The scientific instructional technician or the TA supervising the laboratory will provide specific instructions for the lab session.

Inspect gloves before each use and discard if you see discoloration, punctures, and tears.

Take off gloves before leaving the laboratory. 

Replace gloves often, depending on their frequency of use and permeability of the chemical(s) being handled. Do not re-use disposable gloves. 

Dispose of contaminated gloves by carefully removing them and placing them in the designated waste container. If they are grossly contaminated with hazardous chemicals, then manage them as hazardous waste.

Hair

Any long hair should be tied back or confined when in the undergraduate laboratories to avoid it catching fire, being dragged through chemicals, or becoming entangled in laboratory apparatus.

The rise of physical chemistry

 

The rise of physical chemistry

This is not to say that other approaches to chemistry were neglected, nor that other countries failed to participate in the excitement. Physical studies of chemical compounds and reactions began early in the century, and the field of physical chemistry had achieved maturity by the 1880s. Michael Faraday in England, Hermann Kopp and Robert Bunsen in Germany, and Henri-Victor Regnault in France carried out investigations on the physical characteristics of substances in the period 1830–60. Studies of heat, work, and force led to the rise of thermodynamics around 1850; originally oriented almost entirely to the science of physics, figures such as the American Josiah Willard Gibbs, the Frenchmen Marcellin Berthelot and Pierre Duhem, and the Germans Hermann von Helmholtz and Wilhelm Ostwald then applied energy and entropy concepts to chemistry in the 1870s and ’80s. Electrochemistry, invented by the independent efforts of Berzelius and Humphry Davy in England at the beginning of the century, was pursued fruitfully by Faraday and others. Bunsen and Gustav Kirchhoff of Germany developed chemical spectroscopy in the late 1850s. Studies on the kinetics of chemical reactions began in the 1860s.

All this work culminated in the “official” establishment of the field of physical chemistry, traditionally considered to be when the Zeitschrift für Physikalische Chemie (“Journal of Physical Chemistry”) began publication in 1887. The editors were Ostwald and van ’t Hoff, with Svante Arrhenius of Sweden, a future Nobelist, an especially important member of its editorial board. Controversies over the reality of ionic dissociation and other issues connected with electrochemistry, the theory of solutions, and thermodynamics enlivened early issues of the journal.

Physical chemists were in increasing demand as universities turned to them for instruction in basic courses on general and theoretical chemistry. This was nowhere more true than in the United States, with its vigorously expanding educational structure, including both private and state (land-grant) universities and emerging German-influenced doctoral programs. Soon after the turn of the century, two chemists at the Massachusetts Institute of Technology (MIT) who had studied with Ostwald, Arthur Noyes and Gilbert Lewis, formed the nucleus of a rising American chemical community. Noyes continued his career at Throop Polytechnic in Pasadena (later renamed the California Institute of Technology, commonly known as Caltech), and Lewis went on to the University of California at Berkeley.

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Bohr model of the atomIn the Bohr model of the atom, electrons travel in defined circular orbits around the nucleus. The orbits are labeled by an integer, the quantum number n. Electrons can jump from one orbit to another by emitting or absorbing energy. The inset shows an electron jumping from orbit n=3 to orbit n=2, emitting a photon of red light with an energy of 1.89 eV.

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Rutherford atomic modelPhysicist Ernest Rutherford envisioned the atom as a miniature solar system, with electrons orbiting around a massive nucleus, and as mostly empty space, with the nucleus occupying only a very small part of the atom. The neutron had not yet been discovered when Rutherford proposed his model, which had a nucleus consisting only of protons.

Physical chemistry was profoundly altered by what some have called the second scientific revolution—namely, the discoveries of the electron, X-rays, radioactivity, and new radioactive elements, the understanding of radioactive emissions and nuclear decay processes, and early versions of the theories of quantum mechanics and relativity. All of this happened in just 10 years, from 1895 to 1905, and the scientific bombshells continued in the following years. In 1911 the British physicist Ernest Rutherford proposed a nuclear model of the atom, but his orbiting electrons seemed to violate classical electromagnetic theory, and the model was not immediately embraced. However, two years later the Danish physicist Niels Bohr resolved some of these anomalies by applying spectroscopic data and the quantum theory of the German physicists Max Planck and Albert Einstein to Rutherford’s model (see figure). Bohr went on to head an international theoretical research group in Copenhagen that led in developing quantum mechanics during the 1920s. In the meantime, Rutherford revealed the existence of the proton and Einstein advanced his theory of general relativity.

 Industrial chemistry

The manufacture, sale, and distribution of chemical products is one of the cornerstones of a developed country. Chemists play an important role in the manufacture, inspection, and safe handling of chemical products, as well as in product development and general management. The manufacture of basic chemicals such as oxygen, chlorine, ammonia, and sulfuric acid provides the raw materials for industries producing textiles, agricultural products, metals, paints, and pulp and paper. Specialty chemicals are produced in smaller amounts for industries involved with such products as pharmaceuticals, foodstuffs, packaging, detergents, flavours, and fragrances. To a large extent, the chemical industry takes the products and reactions common to “bench-top” chemical processes and scales them up to industrial quantities.

The monitoring and control of bulk chemical processes, especially with regard to heat transfer, pose problems usually tackled by chemists and chemical engineers. The disposal of by-products also is a major problem for bulk chemical producers. These and other challenges of industrial chemistry set it apart from the more purely intellectual disciplines of chemistry discussed above. Yet, within the chemical industry, there is a considerable amount of fundamental research undertaken within traditional specialties. Most large chemical companies have research-and-development capability. Pharmaceutical firms, for example, operate large research laboratories in which chemists test molecules for pharmacological activity. The new products and processes that are discovered in such laboratories are often patented and become a source of profit for the company funding the research. A great deal of the research conducted in the chemical industry can be termed applied research because its goals are closely tied to the products and processes of the company concerned. New technologies often require much chemical expertise. The fabrication of, say, electronic microcircuits involves close to 100 separate chemical steps from start to finish. Thus, the chemical industry evolves with the technological advances of the modern world and at the same time often contributes to the rate of progress.