Question

E ADVANCED MATERIAL Predicting qualitatively how entropy changes with temperature and volume For each system listed in the first column of the table below, decide (if possible) whether the change described in the second column will increase the entropy S of the system, decrease S, or leave Sunchanged. If you don't have enough information to decide, check the "not enough information" button in the last column. System Change AS O ASCO AS=0 A few grams of liquid acetone (CH),CO). The acetone evaporates at a constant temperature of 62.0 C. ASO not enough information ASO A few moles of carbon dioxide (Co) gas The carbon dioxide is cooled from 73.0 C to -1.0 C and is also expanded from a volume of 5.0 Lt volume of 11.0L ASO not enough Wormation ASCO A few moles of nitrogen (N) gas. The nitrogen is cooled from 70.0°C to 1.0 °C while the volume is held constant at 11.0 L. O AS=0 AS > 0 not enough information Explanation ) Check

Answer 1

a)

Entropy of a system is a measure of its randomness. Gases have more entropy than corresponding liquid due to more randomness.

Thus, for evaporation, $\Delta S>0$

b)

Expanding a system increases the entropy because of increase in randomness. But cooling down decreases the entropy due to particles being more ordered (less random). But here, the system is cooled (decrease in entropy) as well as the volume is increased (increase in entropy). Thus, without additional detail, nothing much can be said. Thus the answer will be not enough information.

c)

Cooling down a system makes particles more ordered, hence it decreases entropy. Thus, $\Delta S<0$