Chapter 18, Problem 3STP

Interpretation Introduction

Interpretation: The missing entries in the given table are to be stated.

$\Delta \text{S}$	$\Delta \text{H}$	$\Delta \text{G}$	Spontaneous
+	-	(a)	Yes
+	(b)	+ or -	At high T
(c)	+	+	No
-	-	(d)	At low T

Concept Introduction: A reaction that favors the formation of the products naturally under the given conditions is called a spontaneous reaction.

Answer to Problem 3STP

$\Delta \text{S}$	$\Delta \text{H}$	$\Delta \text{G}$	Spontaneous
+	-	-	Yes
+	+	+ or -	At high T
+	+	+	No
-	-	-	At low T

Explanation of Solution

An increase in the disorderliness or randomness in the system is defined by a term known as entropy. An increase in the entropy favors the formation of the products, which means for a reaction to be spontaneous, there should be an increase in the entropy.

When the Gibbs free energy of the reaction is negative that means the reaction is spontaneous whereas if the Gibbs free energy of the reaction is positive that means the reaction is non-spontaneous.

At high temperatures, the reaction will be spontaneous when both the change in enthalpy and entropy are positive.

Therefore, the missing entries in the table are given as;

$\Delta \text{S}$	$\Delta \text{H}$	$\Delta \text{G}$	Spontaneous
+	-	-	Yes
+	+	+ or -	At high T
+	+	+	No
-	-	-	At low T