Chemical Thermodynamics Question 397
Question: Which of the following pairs of processes is certain to occur in a spontaneous chemical reaction-
Options:
A) Exothermic and increasing disorder
B) Exothermic and decreasing disorder
C) Endothermic and increasing disorder
D) Endothermic and decreasing disorder
Show Answer
Answer:
Correct Answer: A
Solution:
- Measure of disorder of a system is nothing but entropy. For a spontaneous reaction, $ \Delta G<0 $ . As per Gibbs Helmholtz equation, $ \Delta G=\Delta H-T\Delta S $ Thus $ \Delta G $ is $ -ve $ only when $ \Delta H=-ve $ (exothermic) and $ \Delta S=+ve $ (increasing disorder)
