Answer:
Positive change in enthalpy and negative change in entropy.
Explanation:
Remember that any spontaneous process must lead to a net increase in entropy.
When ΔH>0 and ΔS>0, the reaction proceeds spontaneously at high temperatures and proceeds spontaneously in the reverse direction at low temperatures.
When ΔH>0 and ΔS<0, the reaction proceeds spontaneously in the reverse direction.
When ΔH<0 and ΔS>0, the reaction proceeds spontaneously at all temperatures.
When ΔH<0 and ΔS<0, the reaction proceeds spontaneously at low temperatures and proceeds spontaneously in the reverse direction at high temperatures.
