Chemical Energetics & Thermodynamics

The study of various energies in a chemical paradigm constitutes Chemical Energetics & Thermodynamics. This post shall deal with it as a topic for preparation of JEE Advanced and JEE Mains. The important parts of the chapter and the nature of questions shall also be discussed.


The trends from the previous years’ question papers show that Chemical Energetics and Thermodynamics is one of the more important chapters when it comes to preparation of JEE. Barring 2011, 2012, at least 2 questions from this chapter have appeared every year since 2007 in JEE Advanced, which clearly highlights the weightage of marks that it carries. As far as JEE Mains is concerned, the trend has been relatively staggered, with 1 question being asked in last 3 years and up to 4 questions being asked in the years before that. The questions and concepts are relatively straightforward and hence easier to negotiate.


The high number of questions asked is a direct result of the wide variety of topics that come under this chapter. The most important part is to be thorough with Enthalpy, Entropy, Gibbs’ Free Energy for a reaction and its manipulation according to the requirement. Calculations related to Bond Dissociation Energy etc, all come under this topic. A very important thing for solving the questions is that one should know how to balance chemical reactions.

Sometimes, direct theoretical questions from the laws of thermodynamics are asked. One good look at them should be enough. Another type of important numerical question is the one related Calorimetric calculations.

This chapter being one of the easier ones, can fetch you maximum marks without demanding a lot of effort.

A formula sheet: