Beng 130 Handout-2

# Beng 130 Handout-2 - & First Law of Thermodynamics...

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BENG 130 Thermodynamics System – the part of the universe we’re focusing on Surroundings – everything else Universe =system + surroundings Isolated system – no exchange of any kind with surroundings ( E = 0) Closed system – no exchange of matter, energy changes allowed Open system – can exchange both matter and energy Modes of energy transfer Work (w): Mechanical w=force * displacement & - = 2 1 V V PdV w w=change in kinetic energy=-change in potential energy Mechanical Energy=KE+PE Electrical w=-E*I*t Gravitational w=mg h Heat (q): dq/dT = C C is the heat capacity at constant pressure q p =C p T at constant volume q v =C v T for an ideal gas C p =C v +nR Radiation (r): Photons r = Nhv for N photons of frequency v Black Body r= ± T 4 State Variables Internal Energy (E) monatomic gas nRT E 2 3 = E=q+w

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Unformatted text preview: & First Law of Thermodynamics & E=q v Enthalpy (H) H=E+PV & H=q p Entropy ( S ) dS=dq rev /T & S isolated system ± 0 & Second Law of Thermodynamics For a pure crystal at 0 Kelvin S o =0 & Third Law of Thermodynamics Gibb’s Free Energy (G): useful for reactions at constant T and P G=H-TS Helmholtz Free Energy (A): useful for reactions at constant T and V A=E-TS Types of processes Adiabatic & q=0 Isothermal & & T=0 ( & E=0 for an ideal gas) Isobaric & constant pressure, use C p for heat transfer Isochoric & & V=0 so there is no PV work done, use C v for heat transfer REMEMBERING SIGNS & H < 0 exothermic & H > 0 endothermic & G < 0 exergonic & G > 0 endergonic w > 0 surroundings have done work on system w < 0 system does work on surroundings...
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## This homework help was uploaded on 04/07/2008 for the course BENG 130, 103B, taught by Professor Gough during the Spring '08 term at UCSD.

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Beng 130 Handout-2 - & First Law of Thermodynamics...

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