1. Temperature & Thermodynamics Content from MIT, Mr. Mullins, Mr. Lulai

2. Thermodynamics Big Picture Thermodynamics: Describes macroscopic properties of systems in equilibrium Entirely Empirical Built on 4 Laws and “simple” mathematics System State Properties determine Energy of System cycle.

3. Thermodynamics & Ideal Gases Ideal Gas: Mono-atomic  no rotational energy Collisions are elastic  NRG Conserved Atoms are well-spread out  only atom to atom F are during collisions Large # of particles: statistics work for us

4. Determining System Properties A System at Equilibrium: Defined by macroscopic properties or State variables (p, n, T, V) INDEPENDENT of the HISTORY of the SYSTEM Four Properties Define State of a Gas or System P (Pascal) n T (Kelvin) V (m 3 )

5. System Properties Volume of a Gas (V) volume how much space the gas takes up. NO INDICATION of n Number of Particles (N or n) total number of particles is indicated by “N”. number of moles present in the gas is n Pressure of a Gas (P) Due to particles bouncing off the surface. Temperature of a Gas (T) T K = T C + 273.15 as T k  0 then V  0. If eqn has  T  either Celsius or Kelvin If eqn uses only T then must use Kelvin scale

6. System Properties One-Component (1-gas) System need “n” and 2 variables. All other properties follow: PV=nRT or PV=NkT

7. Thermodynamics Big Picture 0th LawDefines Temperature (T) 1st LawDefines Energy (U) 2nd LawDefines Entropy (S) 3rd LawGives Numerical Value to Entropy These laws are UNIVERSALLY VALID, they cannot be circumvented.

8. Thermodynamics Definitions: System: The part of the Universe that we choose to study Surroundings: The rest of the Universe Boundary: The surface dividing the System from the Surroundings

9. Thermodynamic Systems Systems can be: Open: Mass and Energy can transfer between the System and the Surroundings Closed: Energy can transfer between the System and the Surroundings, but NOT mass Isolated: Neither Mass nor Energy can transfer between the System and the Surroundings

10. System Properties Describing systems requires: A few macroscopic properties: p, T, V, n, m, … Knowledge of System: Homogeneous or Heterogeneous Is System in Equilibrium