Chapter 18, Problem 79A

Interpretation Introduction

Interpretation: Even though the unfavorable entropy change, the steam condenses to liquid water at normal atmospheric pressure is to be explained.

Concept introduction: The process of heat energy being released by molecules is referred to as exothermic. Condensation is an exothermic process because it produces excess heat.

Answer to Problem 79A

At normal atmospheric pressure, the steam turns into liquid water, even though the unfavorable entropy change due to a favorable exothermic change.

Explanation of Solution

At normal atmospheric pressure, the steam condenses into liquid water despite the unfavorable shift in entropy. The favorable change in exothermic energy that results from the condensation process compensates for the unfavorable change in entropy.

Conclusion

At normal atmospheric pressure, the steam turns into liquid water, even though the unfavorable entropy change due to a favorable exothermic change.