Chapter 18, Problem 18.67QP

Interpretation Introduction

Interpretation:

The entropy increase its value in the universe, the reason behind this has to discuss.

Concept Introduction:

Entropy is a thermodynamic quantity, which is the measure of randomness in a system.  The term entropy is useful in explaining the spontaneity of a process. The second law of thermodynamics says that entropy of the universe is increasing. The change in entropy in a phase transition reaction can be found by using the following equation.

${\text{ΔS}}_{\text{sys}}\text{=}\frac{{\text{ΔΗ}}_{\text{sys}}}{\text{T}}$

Where,

  ${\text{ΔΗ}}_{\text{sys}}$ is the change in enthalpy of the system

  $\text{T}$ is the absolute value of the temperature.

For a spontaneous process there is always a positive change in entropy. The second law of thermodynamics says that entropy of the universe is increasing. The change in entropy in the universe is given by the summation of entropy change in the system and surroundings.

${\text{ΔS}}_{\text{univ}}{\text{=ΔS}}_{\text{sys}}{\text{+ΔS}}_{\text{surr}}$