CHEM 1061 Lecture Notes - Lecture 18: Gibbs Free Energy, Enthalpy, Bond Energy
Document Summary
Siepmann: spontaneous process: process that is thermodynamically favored and occurs without external intervention, entropy: measure of accessible microstates, example: expansion of a gas is spontaneous, more microstates available, more variations of configurations of the particles. Positional entropy: positional entropy: depends on the number of configurations (positional microstates) that yield a state. Increased entropy with an increased volume: favorability gas > liquid > solid, gas has more potential configurations. Spontaneous if ssys has a larger magnitude than ssurr. Spontaneous if ssurr has a larger magnitude than ssys. Effect of temperature of spontaneity: ssurr depends on heat flow, exothermic behavior is the driving force for spontaneity. Increased ssurr = increased number of microstates: ssurr = -( h/t) at constant pressure. Characteristics of entropy change the sign of ssurr depends on the direction of heat flow: exothermic = + ssurr, endothermic = - ssurr, magnitude of ssurr depends on temperature, directly proportional with the quantity of heat.
