Chapter 2.3 Entropy & Spontaneous Change

(2.3) entropy & spontaneous change spontancity favours reactants or products → whether equilibrium favours Spontaneous processes occurs in the abscence of any. processes that are can determine of any ongoing outside intervention spontaneous in one direction are non-spontaneous if process is spontaneous through in other enthalpy free energy chopy entropy > measure of system (higher randomnest in system of possibilities higher contropy) Imising of gaces is Increasing entropy (cannot de-mix) spontaneous rans oven't necessant mecastanly AS- fast (cntropy not related to ren vate) SFinal - Sinikal → entropy (s) is a state function products reactants AS depends only on initial & final states if AS > O(+), increasing entropy if AS S_{iiguid}>S_{rolid}\) meterg kumperat bolling fonpcrature entropy change much larger than solid to siguid (ie) evaporation of water \(H_{2}O_{12)}\rightarrow H_{2}O_{(g)} \Delta S=S_{gat}-S_{nqutd}\) melting of water Hapers HD) \(\Delta S=S_{iipuid}-S_{isiid}\) Sublimation of dryice COsm (Dong \(\Delta S=S_{d}\) 00 Du all greater than D increasing temp can Increase vibrational motion, increasin increasing entropy @absolute zero, substance only has zevo-point vibrational energy (or) no translatiomall rotational atomme or as it worms, vibrational motion results molecular positions in a larger distribution of Increase in entropy CHEMICAL RINS) inwcasing # of molecules in Imore freedom of motion : entropy (m gas phase inorcases ontropy gas phase • (is) decomp of NxD. \(O_{2}N-NO_{2}(g)\rightarrow2NO_{lrg)}\) \[\Delta S=S_{x~max}-S_{1~max\] of 20 wery spontaneous process Second law o increases thurmodynamics entropy of the universe \((\triangle S_{arrv}>0)\) since it has contributions from system & surroundings d \[\Delta S_{amiv}=\Delta S_{ay!}+\Delta S_{mar}>0\] • if process causes overall inorcase in onmopy to universe, its spontaneous Standard molar enthalpies 3 daw = the entropy of be sevo (OK) S values in table given a perfectly ordered crystalline solid is defined to [\triangle S^{}=\sum{S^{}}{preduLTI}-\sum{S^{*}}{reattponrs}] Extrapy S