Chapter 15.5, Problem 48SSC

Interpretation Introduction

Interpretation:

The spontaneous and non-spontaneous reactions needs to be compared.

Concept introduction:

Spontaneous reaction: A reaction is spontaneous if it can take place of its own or by some initiation.

Non-Spontaneous reaction: A reaction is non-spontaneous if it can’t take place by strong initiation.

Answer to Problem 48SSC

• A reaction is spontaneous if its Gibbs free energy change is negative and non-spontaneous if its Gibbs free energy change is positive.
• An endothermic reaction may be non-spontaneous at low temperature and spontaneous at high temperature while exothermic reaction may be spontaneous at low temperature and non-spontaneous at high temperature

Explanation of Solution

	Spontaneous reactions	Non-spontaneous reactions
Definition	A reaction that can take place of its own or by some initiation	A reaction is that can’t take place even by strong initiation.
Gibbs free energy change	$\Delta G<0$	$\Delta G>0$
Enthalpy change	Generally, $\Delta H<0$	Generally, $\Delta H>0$
Entropy change	Generally, $\Delta S>0$	Generally, $\Delta S<0$
Effect of Temperature	Exothermic reactions favored at low temperature and Endothermic reactions favored at high temperature	------

Conclusion