Laws of Chemical Combination

When 2 or more substances react chemically a compound is formed. The force which holds the ions together, atoms and molecules in a chemical substance is known as chemical bond. It is the same force which makes the substances combine with each other in several different ways to give newer products and this is called as chemical combination. The combining tendency of atoms to form chemical bonds can be explained in the term of electronic theory of valency, which states that: tendency of an atom to take part in chemical combination can be determined by the number of valence electrons, The atoms acquire the stable noble gas configuration of having 8 electrons in outermost shell by mutual sharing or by transfer of 1 or more electrons, The valency of an element is equal to the number of valence electrons.  There are few laws which direct formation of the chemical compounds. There are several aspects of a chemical reaction such as the rate of reaction, energy absorbed or evolved, mechanism of a reaction which can be evaluated only with the weight and volume relationships. Substances react by certain laws called as laws of chemical combination.

They are given as follows: Law of Conservation of Mass states that the matter can neither be created nor be destroyed. In the chemical reaction the total mass of the reactants is equal to the total mass of the products. Law of Definite Proportions states that a chemical compound has the same elements in the fixed ratio by weight. Law of Multiple proportions states that when 2 elements combine to form 2 or more compounds, the different weights of one of the elements which are combined with the constant weight of the other bears a simple numerical ratio to one another. Law of Reciprocal Proportions states that the ratio among the weights of 2 elements which combine with the fixed weight of the 3rd element will be same or simple multiples of the ratio in which the elements combine together. Law of Combining volumes states that volumes of reacting gases and product gases if any beat a simple numerical ratio to one another.