Question 9.19 (Sixth Edition)

[Steve Magana 2I]

Question: Calculate the standard entropy of vaporization of water at 85 degrees Celsius, given that its standard entropy of vaporization at 100. degrees Celsius is 109.0 J.K^-1.mol^-1 and the molar heat capacities at constant pressure of liquid water and water vapor are 75.3 J.K^-1.mol^-1 and 33.6 J.K^-1.mol^-1, respectively, in this range.

I'm not sure on where to start on this question, can someone help me get started? Thank you!

[Charles Hood Disc 1C]

This question needs to be done in parts, remember that entropy is a state function, so as long as you end up with 85 being your final temperature, you can do whatever you want along the way. Try splitting up the entropy into 3 parts: what it takes to go from 85-100, at 100, then back down again.