Chapter 12, Problem 12.5DQ

Interpretation Introduction

Interpretation:

How the internal energy and entropy of a system composed of two levels vary with temperature has to be explained.

Concept Introduction:

Entropy:

Entropy is the measure of randomness of a system. It is the measure of how the molecules are disordered in a system. It is represented by the letter $\text{S}$.

Internal energy:

Internal energy is the sum of the kinetic and potential energies of a system. So, it is the energy that is arising from the positions and interactions of the molecules in a system. It is represented by the letter $\text{Q}$ .

Relation between entropy and internal energy:

The mathematical expression for entropy according to the 2^nd law of thermodynamics relates the entropy with the internal energy as shown here:

  $\begin{array}{c}\Delta \text{S}\text{=}\frac{\text{ΔQ}}{\text{T}}\\ \Delta \text{S}\text{=}\text{Change}\text{in}\text{Entropy}\\ \text{ΔQ}\text{=}\text{Change}\text{in}\text{internal energy}\\ \text{T}\text{=}\text{Temperature}\end{array}$