The sublimation of "dry ice" is spontaneous at 25 $\circ$ C and 1 atm.What are the signs of $\Delta$H $\circ$ and $\Delta$S $\circ$ ,respectively?
A)0,+
B)+,-
C)-,+
D)+,+
E)-,-

Question

Quizplus · Accepted Answer

Since the process of sublimation is spontaneous, the sign of ∆H is negative, indicating the release of heat. Thus, ∆H is negative, which corresponds to a negative sign in the answer choices. The sign of ∆S is positive since the number of accessible microstates increases during sublimation. Thus, ∆S is positive, which corresponds to a positive sign in the answer choices. Therefore, the best choice is D, which has both answer choices as positive.

The Sublimation of "Dry Ice" Is Spontaneous at 25 ∘\circ∘ C and 1 Atm

The Sublimation of "Dry Ice" Is Spontaneous at 25^$\circ$C and 1 Atm