As always… OWL Lon-Capa assignments Lecture videos Textbook HW due tonight Quiz this weekend Lecture videos Textbook Read Do text homework Video for Wednesday (10/18): Reversible Processes

Clicker Question Is the “pop bottle reaction” spontaneous or not spontaneous? a) Spontaneous b) Not spontaneous

How to Think About Entropy Entropy is related to heat/temperature. ΔS = qrev/T Entropy as “disorder”. S = k●logW

Temperature: measure of KEavg

From the videos and text… …show how probability plays into all of this. …show that thermal equilibrium is preferred when two bodies of different temperatures are put in contact with one another. …see why entropy is related to the logarithm of the number of configurations or microstates. …discuss what “reversible” means when we say the change is entropy equals qrev/T?

Microstate fraction vs. mole fraction

Clicker Question The following chemical reaction is exothermic: A2 + B2  2AB. This means: more stable higher average bond energies a) Reactants Reactants b) Reactants Products c) Products Products d) Products Reactants e) I do not know.