01:160:163 Lecture Notes - Lecture 21: Jmol, Spontaneous Process, Molar Mass
19 May 2016
School
Department
Course
Professor
Document Summary
The first law of thermodynamics: energy can not be created or destroyed, only change form, therefore . The second law of thermodynamics: the total entropy change of the system must be positive for the process to be spontaneous. Mathematically, the irreversible and spontaneous rxn has : And then the nonspontaneous and reversible process rxn has: Third law of thermodynamics: for a perfect crystal at absolute zero, the absolute entropy is 0 j/mol*k. So we can conclude that all substances that aren"t perfect crystals have some sort of energy from entropy. The change in entropy is the difference between entropy at the final and initial states. S gas > s liquid > s solid. Increases with mobility of a phase (elements with at least two allotropes) The less constrained the structure of the allotrope, the larger the entropy. Increases when moles of product are more than moles of reactants.
