Question

For a reaction to be spontaneous under standard conditions at all temperatures, the signs of δh° and δs° must be __________ and __________, respectively.

Answer 1

For a reaction to be spontaneous under standard conditions at all temperatures, the signs of ΔH° and ΔS° must be negative and positive, respectively.
Gibbs free energy (G) determines if reaction will proceed spontaneously, if ΔG is negative, reaction is spontaneous.
ΔG = ΔH - T·ΔS.
ΔG - changes in Gibbs free energy.
ΔH - changes in enthalpy.
ΔS - changes in entropy.
T is temperature in Kelvins.