Notes and Study material for Exams
Valency Valency of an element is a measure of its combining power with other atoms when it forms chemical compounds or Molecules. The combining power, or affinity of an atom of a given element is determined by the number of hydrogen atoms that it combines with. In methane, carbon has a valence of 4; in … Read more
Molecules Molecule, a group of two or more atoms that form the smallest identifiable unit into which a pure substance can be divided and still retain the composition and chemical properties of that substance. The division of a sample of a substance into progressively smaller parts produces no change in either its composition or its chemical properties until parts … Read more
The Rate of a Chemical Reaction can be defined as the amount of the reaction which occurs in unit time. The rate of a reaction is measured by choosing certain properties of the reaction which will indicate how far the reaction has gone, and whose magnitude can be observed with time without disturbing the reaction. … Read more
Acid An acid is a substance which forms H+ ions as the only positive ion in aqueous solution. Examples:- Hydrochloric acid dissolved in water forms H+ and Cl– ions HCl —> H+ + Cl– Sulphuric acid dissolved in water forms H+ and SO42- ions H2SO4 —>2H+ + SO42- Nitric acid forms H+ and NO3– ions when dissolved in water HNO3 —> H+ + NO3– … Read more
Soil consists of rock and sediment that has been modified by physical and chemical interaction with organic material and rainwater, over time, to produce a substrate that can support the Growth of Plants.” Soils are an important natural resource. They represent the interface between the lithosphere and the Biosphere – as soils provide nutrients for … Read more
Chemical kinetics Chemical kinetics is that branch of chemistry which deals with the study of the speeds or the rates of chemical reactions, the factors affecting the rates of the reactions and the mechanism by which the reactions proceed. It concerns itself with the measurement of rates of reactions proceeding under the given conditions of … Read more
Thermodynamics Thermodynamics is a branch of physics which deals with the energy and work of a system.Thermodynamics is the study of macroscopic systems for which thermal effects are important. These systems are normally assumed to be at equilibrium, or at least, close to equilibrium. Systems at equilibrium are easier to study, both experimentally and theoretically, … Read more
Properties of matter Matter is anything that has mass and takes up space. At a minimum, matter requires at least one subatomic particle, although most matter consists of atoms. The two properties of matter are: • Mass – amount or quantity of matter • Volume – amount of space occupiedphysical properties – inherent characteristics of … Read more
Method of production manufacture [water, washing soda, baking soda bleaching powder] Washing soda The chemical name of washing soda is sodium carbonate decahydrate, and its chemical formula is Na2CO3.10H2O. So washing soda is hydrated salt of sodium carbonate containing 10 Molecules of water of crystallization. Sodium carbonate is manufactured by Solvay process. The manufacture of … Read more
Climate Change It is the long term change in the statistical distribution of weather patterns over periods of time Though it has been happening naturally for millions of years, in recent years it has accelerated due to anthropogenic causes and has been causing Global Warming. UNFCCC defines Climate Change as – “a change of climate … Read more