Lyndons practice midterm

[Rebecca Doan 2L]

Can someone please explain to me this concept: "True/False: One cannot calculate the entropy of vaporization for water at room temperature because water has a boiling point of 373K."?

[Samira 2B]

As Lyndon said in the review, water can evaporate in a room that is room temperature without having to reach boiling point. If you think of the temperature change graphs, a phase change is one where the temperature does not have to change. Thus, the temperature does not have to change for there to be a phase change

[404995677]

Also during the review, Lyndon asked "when you spill water does the water just stay there?" No because the water eventually evaporates. The process is 1)water @ 298K to water @ 373K 2)water phase change from gas to liquid 3)water @373K to water @298K. I think :D

[Chem_Mod]

Keliana is listing the steps you could take to calculate the entropy of vaporization for water at room temperature. Please note that the 3rd step should be water vapor gas @373K to water vapor gas @298K. Since entropy is a state function, solving for entropy in this manner works because the initial and final states are the only ones that matter. For further clarification, feel free to drop into Hedrick Room 125 Monday, 2/12 from 5-7pm, where I will be covering for Michael's UA session. -Lyndon