At what temperatures will a reaction be spontaneous if ΔH = -12.7 kJ and ΔS = +135 J/K? (Multiple Choice)?
a.) The reaction will be spontaneous at any temperature.
b.) All temperatures above 94.1 K.
c.) Temperatures between 12.7 K and 135 K.
- ChemTeamLv 72 months agoFavorite Answer
ΔG = ΔH - TΔS
At equilibrium, ΔG = 0
0 = -12700 - (T)(+135)
12700 = - (T)(+135)
Do you see how T will wind up to be a negative value. Which is, of course, an impossible value.
Hence, answer choice a is the correct answer.
Another way to say it is that no value of T will ever give a value of 0 for ΔG, it will always be negative.