Chemical Reaction on the Basis of Heat Evolved
On the basis of Heat Evolved, the chemical reactions are classified as follows:
- Exothermic Reaction
- Endothermic Reaction
Exothermic Reaction
Exothermic Reaction is a chemical reaction in which the heat energy get released after the reaction has happened. In case of exothermic reaction, the change in enthalpy is negative ΔH = -ve. Combustion Reaction is an example of exothermic reaction. Following equation represents combustion of methane
CH4 + 2O2 → CO2 + 2H2O + Heat
In above example, the ethanlpy change is ΔH = -890 kJ/mole
Endothermic Reaction
Endothermic Reaction are the chemical reactions which absorbs heat to proceed the reaction and form the product. Endothermic Reaction is just opposite of Exothermic Reaction. In case of Endothermic Reactions, the enthalpy change is positive which is given as ΔH = +ve. Sublimation, Hydrolysis, Thermal Cracking etc. are few examples of Endothermic Chemical Reaction. An example of Endothermic Reaction is mentioned below:
C6H12O6 + 6 H2O → 12H2 + 6 CO2
Here, in the above example the change in enthalpy is ΔH = +627 kJ/mol
Chemical Reactions
Chemical Reaction is the disruption of existing bonds within reactant molecules and the creation of fresh bonds in product molecules, culminating in the formation of a new substance. These reactions are all around us, spanning from the biochemical processes in our bodies that extract energy from food to the source of sunlight, where chemical reactions are used to produce the light we receive.
In this article, we will understand the meaning and characteristics of Chemical Reactions. This article will cover the various types of Chemical Reactions: Combination or Synthesis Reaction, Decomposition Reaction, Single Displacement Reaction, and Double Displacement Reaction. We also discuss factors affecting the rate of Reaction and practice questions to understand this article.
Table of Content
- What is a Chemical Reaction?
- Characteristics of a Chemical Reaction
- How would we know when a Reaction has taken place?
- Chemical Equation
- Balancing a Chemical Equation
- Types of Chemical Reaction