[poll id=”46″]
ANSWER: B – Spontaneous at high temperatures
A reaction with positive entropy and enthalpy means it is spontaneous at high temperatures (e.x. boiling). Whereas a reaction with both negative values for enthalpy and entropy means it is spontaneous at low temperatures only. A positive ΔS and a negative ΔH means the reaction is spontaneous at all temperatures, whereas the inverse (negative ΔS and positive ΔH) is not spontaneous at all temperatures.