1. CHEM 433 – 9/22/11 II. Gases – finish van der Waals Equation. (1.4) III. 1st Law of Thermodynamics (Chapter 2) - Introduction & Definitions (2.1) - Internal Energy (2.2) - The 1st LAW (2.2) READ: CH #2 (you will not do this ‘til after the test). Exam rev. sheet updated – (covers thru “gases”) HW due tomorrow – in class.

2. How would you expect a & b values to vary across the series: H 2 O, NH 3, CH 4 ? a(Latm/mol 2 ) b(10 -2 L/mol) CH 4 : 2.27 4.31 NH 3 : 4.17 3.71 OH 2 : 5.46 3.05

3. vdW Isotherms get weird …

5. Thermodynamics: The study of energy transformations. System: For us this almost always means the molecules themselves. Surroundings: Everything that is not the system. (Where we measure…) Universe: Everything - I.e. The system and the surroundings. Open System: Exchanges matter and energy w/ surroundings. Closed System: Exchanges energy but not matter, w/ surroundings. Isolated System: Does not exchange matter or energy w/ surroundings.

6. Work: When an object is moved against an opposing force (W = F x d). Energy: Capacity to do work. Heat: A means by which the energy of a system can change without work. Diathermic Boundary: Allows transfer of heat. Adiabatic Boundary: Does not allow transfer of heat. Exothermic Process: System releases heat (q 0). Endothermic Process: System absorbs heat (q>0). (This means  Tsurr< 0).

7. Internal Energy (U): Total Kinetic and Potential Energy of the System. State Function: A property whose value depends solely on the current state of the system – not on the nature of the change that got it to that state (I.e. the path) Adiabatic Process: No heat transferred (q=0) Isothermal Process: No Temperature change (  T=0). BTW: A “process” is a change of state (i.e. in P,V, and/or T), a reaction, change in physical state ((g)—> (l)) etc. …