Chem 102 1st Edition Lecture 14 Outline of Last Lecture I. First Law of ThermodynamicsA. Spontaneous ProcessII. Entropy and Second Law of ThermodynamicsIII. Molecular Interpretation of Entropy ChangesA. Calculations of Entropy ChangesOutline of Current LectureI. Gibb’s Free EnergyII. Free Energy and TemperatureIII. Free Energy and The EquilibriumCurrent LectureI. Gibb’s Free Energy- G, for a spontaneous reaction the entropy of the universe must increase. G= H-TS. 3 important conditions: G<0 the forward reaction is spontaneous. If G=0 then the reaction is at equilibrium and no net reaction will occur. If G>0 the forward reactionis not spontaneous. For a reaction, the free energy of the reactants decreases to a minimum(equilibrium) and then increases to the free energy of the product. -Free energy change- change in G, is the free energy change that occurs for reactants in one set of specific states are converted to products in one specific set of states. -Standard Free energy change- Change in G, is the free energy change that occurs if allthe reactants in their standard states are converted to products in their standard states. II. Free Energy and Temperature- If DH < 0 and DS > 0, then DG is always negative.If DH > 0 and DS < 0, then DG is always positive. (That is, the reverse of 1.)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.If DH < 0 and DS < 0, then DG is negative at low temperatures.If DH > 0 and DS > 0, then DG is negative at high temperatures.-Even though a reaction has a negative change in G, it may occur too slowly to be observed. Thermodynamics gives us the direction of a spontaneous reaction not its rate. III. Free Energy and The Equilibrium- Equilibrium constants refers to standard conditions while the equilibrium quotient refers to all conditions. So;If DG° < 0, then K > 1.If DG° = 0, then K = 1.If DG° > 0, then K <
View Full Document