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Action of Alkalis on Substances |
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It is well known that a base is a substance that combines with an acid to form salt and water only. |
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Carbon Compounds |
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Carbon compounds are of two types: inorganic and organic. The compounds that have a mineral origin fall under the category of inorganic compounds. The compounds having plant or animal origin are classified as organic compounds. Lavoisier showed that nearly all compounds of plant origin are composed of carbon, hydrogen and oxygen. While those of animal origin also had other substances like nitrogen, sulphur or phosphorus. In spite of the fact that organic compounds were originally derived from living sources, today, most of these compounds can be synthesized. |
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Chemical Bonding |
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Atoms of elements combine to form molecules of compounds. This combination can occur in two ways: either by electrovalent bonding or covalent bonding. In all chemical reactions it is the electrons from the outermost shell of an atom that are involved in interacting with other atoms, either by their transfer or by sharing. |
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Compounds of Nitrogen |
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Joseph Priestley first prepared ammonia in 1775 by heating Sal ammoniac (ammonium chloride) with slaked lime. Due to its basic nature, he called it alkaline air. In 1785, Comte Claude-Louis Berthollet determined the chemical composition of ammonia. |
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Compounds of Sulphur and their Properties |
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Sulphur dioxide has been known to people for ages. Sulphur used to be burnt to produce sulphur dioxide, which was then used as a fungicide and insecticide. Priestley prepared sulphur dioxide in the year 1774 by heating concentrated sulphuric acid with mercury and called it "Vitriolic acid air". But it was Lavoisier, who proved that it was an oxide of sulphur. |
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Electrolytes Non-Electrolytes and Electrolysis |
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In any chemical reaction, the existing chemical bonds are broken and new chemical bonds are formed. Hence, all chemical reactions are fundamentally electrical in nature since electrons are involved in some way or the other in all types of chemical bonding. Many chemical reactions utilize electrical energy, whereas others can be used to produce electrical energy. As electrical energy involves the flow of electrons, these reactions are concerned with the transfer of electrons from one substance to the other. |
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Hydrogen Chloride and Hydrochloric Acid |
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Even in the sixteenth century chemists knew that by heating common salt and concentrated sulphuric acid together, hydrogen chloride could be prepared. The sodium sulphate salt obtained during the reactions studied intensively for its properties is called Glauber's salt after the discoverer Johann Glauber. |
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Laboratory Preparation of Salts |
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Salts are generally ionic compounds formed by the reaction of an acid with a base. The preparation of these salts involves the treating of different metals and non-metals and their compounds with various acids, bases etc. However, some of them can be prepared by direct combination of the concerned elements or also by indirect routes. |
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Metals and Non-metals |
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Earth is an abundant source of material. Man has intensively studied the properties of these materials extensively and found new methods of using them. The air we breathe, the water we drink, stones and rocks, almost everything that is around us, are all useful to man for some purpose or the other. These materials are distributed in the atmosphere, lithosphere, and hydrosphere. Oxygen, Nitrogen and Carbon di oxide are found in the atmosphere. Common salt and various other salts of sodium, magnesium and calcium are found dissolved in water bodies, like the oceans, rivers and lakes. |
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Mole Concept and Stoichiometry |
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In the year 1801, Robert Boyle and Charles had deduced the gas laws and proved them. They had confirmed that equal volumes of all the gases behave similarly, under similar conditions of temperature and pressure and the volumes of reacting gases and their gaseous products are in ratio of small whole number. In 1811 Amedeo Avogadro was able to explain Boyle's and Charles' Law on the assumption that equal volumes of different gases, under the same conditions of temperature and pressure, contain the same number of particles. |
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Periodic Properties and their Variations |
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The physical and the chemical properties of elements are periodic functions of their atomic numbers. |
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Rate of Chemical Reaction and Chemical Equilibrium |
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We observe various chemical processes in our daily life. It is a common observation that the rates of these chemical reactions vary and depend on certain factors. The knowledge of the rate of a reaction is of importance in industries to ensure optimum productivity. |
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Some Important Chemical Compounds |
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Sodium belongs to Group I in the periodic table. This group is otherwise known as the alkali metals group. Since the atomic number of sodium is 11, its electronic configuration is 2,8,1. Sodium easily loses the lone electron to attain the stable configuration of neon. Therefore alkali metals like sodium that are univalent can easily form ionic compounds. Sodium bicarbonate (NaHCO3) is an example for the univalent nature of sodium. |
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Study of Acids Bases and Salts |
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Acids, bases and salts are three main categories of chemical compounds. These have certain definite properties that distinguish one class from the other. Scientists like Lavoisier and Davy studied acids and bases in a scientific manner. Initially, Lavoisier believed oxygen to be a constituent of all acids. It led him to frame the word "oxygen" which means "acid producer". Later, Davy was able to disprove this wrong notion, by preparing hydrochloric acid, which does not have oxygen. |
