Chemical Reactions

Chemical Reactions: A reaction is defined as the process to produce a new product according to desire.Chemical reactions are the reactions carried out between various chemicals or mixtures or compounds to carry out a product.First of all let see among which components the chemical reactions are carried out to obtain a product.

Reactants: Reactants are the mixtures or compounds which either combines with each other or dissociates to obtain a new products. Reactants are the compounds which carry out the reaction. For example evaporation of water. If we keep a plate contain some water in it in contact of sun light . Water will evaporate. Here the water is a reactant which carry out the reaction.

Products:Products are the compounds or mixtures which are produced after completion of reaction.for example if we carbon with oxygen gas carbon dioxide is produced. Here carbon dioxide is a product.

Catalyst:catalyst are the compounds or elements which help to carry out the reaction but they do not enter in the reaction means they are not consumed during the reaction. Catalyst are used either to speed up the reaction or to slow down the reaction but they never consumed in the reaction..Catalyst acts as a surface on which reaction occurs.For example during the conversion of vanaspati ghee into vanaspati oil hydrogen gas is passed with high pressure on the vanaspati compounds in the presence of platinum metal .Here platinum works as a catalyst.

Here I am going to define various types of chemical reactions:

Endothermic Reactions:Endothermic reaction is the reaction in which heat is absorbed to complete the reaction. These reactions are carried out by heating the reactants. we can take evaporation of water as an example in which evaporation of water occurs after water is heated up up to its boiling point.

Exothermic Reactions:Exothermic reactions are those which are carried by emitting of heat. It means heat is released while completion of reaction.For example:when calcium carbonate is dissociated calcium oxide and carbon dioxide is produced as product along with it heat is also released in reaction.

CaCO3 --> CaO + CO2 + Heat

Substitution Reaction:This is the reaction in which elements of one compound substitute or replace elements of other compound to obtain a product.For example lets see a reaction: CuSO4 + Zn --> ZnSO4 +Cu. Here zinc replaces copper from copper sulphate and forms zinc sulphate.

Addition Reaction: Reaction in which two or more reactants combined to produce a product.For example: C+O2 --> CO2.

Dissociation Reaction: Reaction in which reactant dissociates to produce two or more products.For example: Caco3 --> CaO + CO2 + Heat.

Hydrolysis Reaction: Reaction in which one of the reactant is water is called hydrolysis reaction.For Example: Ca + H2O --> Ca(OH)2 + H2