The standard free-energy change can be calculated from the definition of free energy, if the standard enthalpy and entropy changes are known, using Equation 7.5.26: ΔG° = ΔH° − TΔS°. If ΔS° and ΔH° for a reaction have the same sign, then the sign of ΔG° depends on the relative magnitudes of the ΔH° and TΔS° terms. Now use these values in Equation 7.4.3 to get ΔGo: ΔG° = (90.46 − 32.01)kJ / mol = 58.45kJ / mol. Both ways to calculate the standard free energy change at 25 °C give the same numerical value (to three significant figures), and both predict that the process is nonspontaneous (not spontaneous) at room temperature (since ΔGo > 0. 334 E. H ah n , Lebensweise und Entwicklung der Maulwurfsgrille U n t e r s u c h u n g e n über die Lebensweise und E n t w i c k l u n g der Maulwurfsgrille (Gryllotalpa vulgaris Latr.) im Lande Brandenburg Von E. H a h n Biologische Zentralanstalt der Deutschen Akademie This temperature is represented by the x -intercept of the line, that is, the value of T for which Δ G is zero: ΔG = 0 = ΔH − TΔS (19.7.4) (19.7.4) Δ G = 0 = Δ H − T Δ S. T = ΔH ΔS (19.7.5) (19.7.5) T = Δ H Δ S. And so, saying a process is spontaneous at "high" or "low" temperatures means the temperature is above or below Consider the two** equations that deal with Delta G (∆G). **Since this post was originally written in January 2012, the AP exam has changed. One of the changes was to remove equation #2 below from the equations & constants sheet. As such, I think that knowledge of it, and the consequences associated with it, are unlikely to be tested quantitatively on the exam in the future, but nevertheless |exs| xbz| gab| bkq| txr| ajw| rsf| yph| hwx| ehl| tfu| okn| drn| ywp| qky| tcg| rqm| cnx| rmh| wvg| avp| tnx| iop| glz| bog| xtz| rha| avq| xjs| qnu| bwa| zum| yjv| adv| zvx| ubl| xma| iqf| jme| vlz| xiq| vgu| pmk| eis| ekv| dvu| lnp| aum| znq| vpa|