The first ph d in science awarded by american

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Unformatted text preview: Gibbs Free Energy G Josiah Willard Gibbs (1839-1903) (1839American Physicist, chemist & Mathematician One of the greatest American Scientists of all time! The first Ph. D in science awarded by American University! The first to apply the second law of thermodynamics thermodynamics to the exhaustive discussion discussion of the relation between chemical, chemical, electrical, and thermal energy and capacity of external work! capacity Father Father of physical chemistry! Coining the term: “enthalpy”, “Gibbs free energy”, “Gibbs entropy”, “vector analysis”, “Gibbs phase rule”, “Gibbs state”, “Gibbs-Thomson effect”... Gibbs- Founder Founder of physical thermodynamics Gibbs Gibbs Free Energy G Laws Laws of Thermodynamics show that spontaneity is predictable by considering two factors: Enthalpy & Entropy Entropy H S ∆H of the reaction large large & negative tends to negative tends occur occur spontaneously! Josiah Willard Gibbs: Entropy of Entropy of a reaction: Increase tends Increase tends to occur occur spontaneously! G = H − TS Free Energy: net amount available for useful work after considering the two factors Free Free energy change G The change in free energy of a chemical reaction: ∆G = G products − Greac tan ts At constant temperature : ∆G = ∆H − T ∆S G : maximum amount of useful energy obtained from the reaction - T S = energy “wasted” due to entropy factor. H: enthalpy change (energy from the reaction) Gibbs Gibbs Free Energy (G) For a constant-temperature process: constant- ∆rG = ∆r H − T ∆r S ∆rG < 0 Free energy always decreases → Energy releases as reaction occurs Free energy reaches a minimum value ∆rG = 0 Occurs in either direction equally → Reactions stops at this point ∆rG > 0 Free energy always increases Requires energy for → the reaction to occur Spontaneous Process At Equilibrium Non-spontaneous Process Standard free energy of formation ∆G o f The free-energy change that occurs when 1 mole f...
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