L23S07_ThermoFirstLaw 03-12-07

L23S07_ThermoFirstLa - Chem 1A"Thermodynamics First Law" Real Gas Behavior P =Summary Tc V V 1 V V P P Ideal PV=const

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Unformatted text preview: Chem 1A: "Thermodynamics, First Law" Real Gas Behavior P =Summary Tc V V 1 V V P P Ideal: PV=const A.Pines,M.Kubinec,UCB Real: PV = ? L16-21 2004 M. Kubinec L24-1 CO2 S P Phase Diagram L Triple Point TTP = -56.6 oC PTP = 5.1 atm G Temperature Tc L24-2 2004 M. Kubinec ChemQuiz 22.2 Which plot corresponds to the process shown ? P S L G P P P T Tc 1) 2) V V 3) V L24-3 2004 M. Kubinec A.Pines,M.Kubinec,UCB 1 Chem 1A: "Thermodynamics, First Law" H2O S P Phase Diagram L Triple Point TTP = 0.01 oC PTP = 4.6 torr G Temperature Tc L24-5 2004 M. Kubinec ChemQuiz 22.3 P Which is a plot of the vapor pressure of water vs. T ? P P S L G P T Tc 1) T 2004 M. Kubinec 2) T 3) T L24-6 ChemQuiz 22.4 Which is the 373 K isotherm for water ? P S A B C L G T Tc 1) A 2004 M. Kubinec 2) B 3) C L24-8 A.Pines,M.Kubinec,UCB 2 Chem 1A: "Thermodynamics, First Law" First Law of Thermodynamics w:work + System (you can't win) Work for Gases Pext = F/A Summary E = q + w Conservation of E E is a state function Euniv = Esys + Esurr = 0 L22-4 w = - F h = - Pext V hh3 E = 2 nRT Expansion Compression 3 - + q:heat V > O w<O A.Pines, M.Kubinec,UCB V < O w>O L29-6 Surroundings A.Pines, M.Kubinec,UCB Isothermal Expansion/Compression Pext = F/A Adiabatic Expansion/Compression Pext = F/A Const T : E = H = 0 hh- q = 0 : E = w hhExpansion w<O E < O A.Pines, M.Kubinec,UCB q + ww 0 =- = Expansion wq+ Compression w+ qL22-12 Compression w>O E > O A.Pines, M.Kubinec,UCB A.Pines, M.Kubinec,UCB L24-10 L22-14 First Law of Thermodynamics w:work System (you can't win) can' + E = q + w E is a state function Conservation of E - + q:heat Euniv = Esys + Esurr = 0 L24-11 Surroundings A.Pines, M.Kubinec,UCB Work and Energy for Gases Pext = F/A w = - F h = - Pext V h+ E = 2 nRT Expansion 3 Expansion V > O wO V > O w<O L24-12 A.Pines, M.Kubinec,UCB A.Pines,M.Kubinec,UCB 3 Chem 1A: "Thermodynamics, First Law" Work for Gases Pext = F/A w = - F h = - Pext V h- E = 2 nRT Expansion Compression 3 V > O w<O A.Pines, M.Kubinec,UCB V < O w>O L24-13 Constant Volume / Pressure E = q + w Volume Energy E w=0 E = qv E T Bomb Calorimeter A.Pines, M.Kubinec,UCB Pressure L24-14 Constant Volume / Pressure Pext E = q + w Volume Energy E w=0 E = qv E T Pressure Enthalpy H = E + PV H = E + PV P H = qp H T L24-15 Open to Atmosphere A.Pines, M.Kubinec,UCB A.Pines,M.Kubinec,UCB 4 Chem 1A: "Thermodynamics, First Law" ChemQuiz 23.1 An ideal gas expands isothermally against a vacuum.What is q ? vacuum.What Pext = 0 Expansion V > O wO h+ 1) < 0 A.Pines, M.Kubinec,UCB 2) = 0 3) > 0 L24-16 ChemQuiz 23.2 An ideal gas is isothermally compressed. What is q ? h- 1) < 0 A.Pines, M.Kubinec,UCB 2) = 0 3) > 0 L24-18 Isothermal Expansion/Compression Pext = F/A Const T : E = H = 0 Expansion V > O wO h+ q + ww 0 =- = Expansion wq+ L24-20 A.Pines, M.Kubinec,UCB A.Pines,M.Kubinec,UCB 5 Chem 1A: "Thermodynamics, First Law" Isothermal Expansion/Compression Pext = F/A Const T : E = H = 0 h- q + ww 0 =- = Expansion wq+ Compression w+ qL24-21 A.Pines, M.Kubinec,UCB Adiabatic Expansion/Compression Pext = F/A q = 0 : E = w Expansion V > O wO h+ Expansion w<O E < O L24-22 A.Pines, M.Kubinec,UCB Adiabatic Expansion/Compression Pext = F/A q = 0 : E = w hExpansion w<O E < O A.Pines, M.Kubinec,UCB Compression w>O E > O L24-23 A.Pines,M.Kubinec,UCB 6 Chem 1A: "Thermodynamics, First Law" ChemQuiz 23.3 A gas expands adiabatically against a constant pressure. pressure. What happens to the temperature of the gas ? 1) Increases A.Pines, M.Kubinec,UCB 2) Same 3) Decreases L24-24 ChemQuiz 23.4 A stretched rubber band is suddenly released. What happens released. to the temperature of the rubber band ? 1) Increases A.Pines, M.Kubinec,UCB 2) Same 3) Decreases L24-26 Lecture Complete A.Pines, M.Kubinec,UCB L24-28 A.Pines,M.Kubinec,UCB 7 ...
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This note was uploaded on 08/19/2009 for the course CHEM 1A taught by Professor Nitsche during the Spring '08 term at University of California, Berkeley.

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