The practical utility of polymers depends upon their mechanical properties such as, tensile strength, elasticity, toughness, etc. These mechanical properties depend upon the nature and strength of forces acting between the polymeric chains. As a result, therefore, the polymers may be classified into various categories on the basis of strength and nature of intermolecular forces … Read more
Colloids find many applications in our daily life and in industry. Some typical applications of colloids are given below: 1) Food Many constituents of our food are colloidal in nature. For example, milk, starch, proteins, fruit-jellies etc., are colloids. 2) Medicine A large number of medicines and pharmaceuticals preparations are colloidal in nature. Some of … Read more
Colloidal solutions can also be classified on the basis of constitution of the particles of the dispersed phase. The tree types of colloids are given as below: A) Multi-molecular Colloids This is the type of colloid in which the colloidal particles consists of aggregates of atoms or small molecules, having diameters of less than 1nm. … Read more
Generally metals that are most commonly used are strong, ductile and malleable. It get exposed to the environment when it is used due to which many of them will lose their shine, and get covered with coloured layer on them. Some even lose their strength and become weak and brittle. This occurs due to chemical … Read more
The atomic imperfections (defects) are caused by some disorder in the arrangement of the constituent particles in any crystal. There are two kinds of atomic defects. They are i) Point defects ii) Lattice defects Point defects The defects caused by a departure from the periodic arrangement of particles in the vicinity of an atom or … Read more
The rate of reaction is governed by number of factors. Those having appreciable effect are described below: a) Nature of reactants Reactions involving polar and ionic substances including the proton-transfer reactions are usually very fast. On the other hand, the reactions in which bonds are rearranged, or electrons transferred, are slow. Oxidation- reduction reactions, which … Read more
The purification of organic compounds is tedious unlike inorganic compounds because large number of them decomposes on heating, some are sensitive to other reagents and resist the solvent action of water. Depending on the nature of the compound and nature of impurities present, various methods can be employed for the purification of a particular compound. … Read more
Combined gas law states that, for a given mass of a gas, the product of its pressure and volume divided by its Kelvin temperature is a constant. Boyle’s Law and Charle’s Law give separately the effect of pressure and temperature respectively on the volume of a gas. Combined Gas Law or the gas equation gives … Read more
The long form of periodic table can be divided into four main blocks. These four main blocks are s, p, d and f –blocks. The division of elements into blocks is purely based upon the electronic configuration. The nature of the subshell in which the last electron of that atom enters, determines the block to … Read more
Excitation Potential The energy required to raise an atom from its ground state to an excited state is called the excitation energy. Under normal conditions, hydrogen atoms are usually in their lowest energy state where n = 1. This is called ground state of hydrogen atoms. However, if the atoms are exposed to incident energy … Read more