CHEM 10171 Lecture Notes - Lecture 6: Boltzmann Constant, Gibbs Free Energy, Randomness

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Gases: three common phases of matter, solid: close contact between neighboring molecules/ions, regular position, density. Ideal gas law: pv=nrt: pressure: force/area = n/m^2 = kg/s^2 = pa standard chemical unit = 1 bar. If system is pushing against you: +v -w ; system is doing work on surroundings. Thermodynamics: the magic of state functions, there are certain properties that depend only on instantaneous state of a system. In chemistry most reactions are carried out at constant pressure. In general: hrxn =(bde"s of bonds broken) - (bde"s of bonds formed) If break weak bonds and form strong bonds: give off energy hrxn is negative exothermic . Srxn >0: entropy of surroundings might increase, ssurroundings = dqreversiblet=qreversiblet(because of constant, qsurroundingst (for surrounding heat flow is reversible) 1 bar pressure, pure substance: so these conditions in g dictate spontaneity under standard conditions, we can do the same for same trick for free energies that we did for enthalpies and define.