MPPCS Paper III- Chemistry

Matter in our surroundings, Elements, Compounds, Mixtures

Matter in our surroundings, Elements, Compounds, Mixtures Matter is any thing which has mass and occupies space. All solids, liquids and gases around us are made of matter. Scientist believe that matter is made of tiny particles that clump together. You cannot see these particles but you can see the matter, for example, a book, a car, a letter, a hand set, a piece of wood, tree, a bag etc. A substance is a pure kind of matter having only one kind of constituent particle (atom or molecule). Water, iron, gold, copper, aluminum and oxygen are examples of substances. All ... Read more

Metals and Non-metals

Metal   In chemistry, a metal is an element that readily forms positive ions (cations) and has metallic bonds. Metals are sometimes described as a lattice of positive ions surrounded by a cloud of delocalized electrons. The metals are one of the three groups of elements as distinguished by their ionization and bonding properties, along with the metalloids and nonmetals. On the periodic table, a diagonal line drawn from boron (B) to polonium (Po) separates the metals from the nonmetals. Most elements on this line are metalloids, sometimes called semi-metals; elements to the lower left are metals; elements to the ... Read more

Carbon and its compounds

Carbon is the common element found in all known form of life. Structure of all living organism contains carbon. Carbon present in living organism even after death. Coal, petroleum and its products are compounds of carbon. Carbon is an element and a non-metal. Symbol of Carbon = C Atomic number of carbon = 6 Atomic structure of carbon = 2, 4 Valence electrons of carbon = 4 Nature of carbon = Non-metal Since, valency of carbon is equal to four, thus carbon is called tetravalent. Four valency of carbon means, carbon reacts with four atoms of same or different elements ... Read more

Molecules and Atom

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 consisting of single molecules are reached. Further subdivision of the substance leads to still smaller parts that usually differ from the original substance in composition and always differ from it in chemical properties. In this latter stage of fragmentation the chemical bonds that hold the ... Read more

Structure of atom

Atomic Structure In 1897 J.J. Thomson discovered electron as a constituent of atom. He determined that an electron had a negative charge and had very little mass as compared to that of the atom. Since an atom was found to be electrically neutral it was inferred that some source of positive charge must be present in the atom. This soon led to the experimentaldiscovery of the proton, which is a positively charged subatomic particle. Proton was found approximately 1840 times heavier than an electron. Further‘ experiments revealed that the atomic masses were more than that expected from the presence of ... Read more

Chemical Reaction

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. For example, a reaction which shows color change: the rate of such reaction can be measured by observing how the intensity of color formed changes with time. In a similar way, a reaction which involves gases can have its rate measured by collecting the gas ... Read more

Acids, Bases and Salts.

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–   Ethanoic acid,also know as acetic acid, forms H+ and CH3COO– ions in water CH3COOH —> H+ + CH3COO– Acetone, also known as propanone, doesn’t form any ions in water, so it isn’t an acid. CH3COCH3 just dissolves in water. Methane, CH4, doesn’t form any ions in water, so this ... Read more

Nanotechnology

Nanotechnology relates to the technology of rearranging and processing of atoms and molecules to fabricate material to Nano specifications such as nano meters, the technology will enable scientist and engineers to see and manipulate matter at the molecular level atom by atom create new structure with fundamentally new molecular organic material and exploit the novel prospects at that scale Scientific achievements of Nanotechnology the concept was first introduced in the year 1959 by an American scientist Richard Feynman who in his famous lectures there stated that there is a plenty of room left at the bottom indirectly mentioned about the ... Read more

Issues of Direct and Indirect Subsidy for farm sector and other social sectors. 

  Issues of Direct and Indirect Subsidy for farm sector and other social sectors.  Subsidy is one of the powerful fiscal instruments, besides taxes and others, by which the objective of growth and social justice may be achieved.   Subsidies alter relative prices and budget constraints and thereby affect decisions concerning production, consumption and allocation of resources. Like many other countries, subsidies in Indian economy are pervasive. These are explicit or hidden and include the areas such as education, health, environment and variety of economic activities including agriculture and transport. Nearly 66 per cent of the people in India are ... Read more