Chapter 14.5, Problem 5PPC

Interpretation Introduction

Interpretation:

The best answer from the given set of options has to be found.

Concept Introduction:

In thermodynamics a process is spontaneous if it is taking place by itself without the help of external energy.  Free energy (Gibbs free energy) is the term that is used to explain the total energy content in a thermodynamic system that can be converted into work.  The free energy is represented by the letter G.  All spontaneous process will have highly energetic initial state than the final state.  This indicates that while the process occurs, there is a decrease in free energy of the system.  The increase in randomness also favours the spontaneity of a process.  In non-spontaneous process, there is a requirement of external energy source.  The free energy of the system increases.  The entropy decreases in non-spontaneous process.

The equation given below helps us to calculate the change in free energy in a system.

$\text{ΔG = }\Delta {\rm H}\text{- T}\Delta \text{S}$

Where,

$\text{ΔG }$ is the change in free energy of the system.

$\Delta {\rm H}$ is the change in enthalpy of the system.

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

$\Delta \text{S}$ is the change in entropy in the system.