Chapter 18, Problem 18.43SP

Interpretation Introduction

Interpretation:

The exothermic reaction is spontaneous and endothermic reaction are non-spontaneous should be explained.

Concept Introduction:

• Spontaneous reaction: A process which can take place by itself without the help of an external activity under the given set condition is called a spontaneous process. The term spontaneity simply means the feasibility of a process and the spontaneous processes are called feasible processes.
• Non-spontaneous reaction: A process in which one has no tendency to occur or which is forbidden and is made to occur only if external energy is continuously supplied.
• Exothermic reaction: The reaction which releases energy in the form of heat
• Endothermic reaction: The reaction in which heat energy is absorbed from the surrounding.
• Enthalpy $\left(\Delta H\right)$:- It is defined as the sum of internal energy and the pressure-volume energy of the system.
    $\Delta H=\Delta U+P\Delta V$
• Entropy $\left(\Delta S\right)$:-It is defined as a measure of the disorder or randomness of the system. More the randomness , more is the entropy.
    $\Delta S=\frac{q}{\Delta T}$
• Gibb’s free energy $\left(\Delta G\right)$:- It is the amount of energy available from a system that can be converted into useful work. It is a measure of its capacity to do useful work.
    $\Delta G=\Delta H-T\Delta S$

To explain:

The exothermic reaction are spontaneous and endothermic reactions are non-spontaneous.