Chem208_Lecture_22_Color - Today: Thermodynamics (Chapter...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Today: Thermodynamics (Chapter 19) - finish Entropy - Free Energy Pick up or download PS9 today; Due Friday, 4/18, at 2:00 1 Review ∆S can be expressed in terms of several state functions: T, V, P For spontaneous process: ∆Stot = ∆Suniv = ∆Ssurr + ∆Ssys > 0 A system is more likely to be found is a condition that corresponds to more microstates 2 • S°, standard molar entropy, is the absolute entropy possessed by a substance in its standard state • S° increases as the complexity of a substance increases 3 Can we express spontaneity in terms of thermodynamic properties of the system only? ∆G°sys = ∆H°sys -T∆S°sys The importance of the concept of Free Energy is that, provided we can accept the limitation to changes at constant P and T, we can now discuss spontaneity in terms of the thermodynamic properties of the system. 4 Qualitative Meaning of Free Energy • ∆G is the amount of energy released during a reaction that can be used to do work (∆G = – w) 5 Standard Free Energy of Formation, ∆Gf° • Analgous to ∆Hf°; the elements in their standard states serve as the reference against which values of ∆Gf° ( and ∆Hf°) for substances are measured • ∆Gf° = 0 for elements in their standard states Calculate ∆G° for the oxidation of NH3(g) by O2(g) to produce NO(g) and H2O(l) 6 ...
View Full Document

Page1 / 6

Chem208_Lecture_22_Color - Today: Thermodynamics (Chapter...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online