CHEM 1032 – Fall 2022 Week 5
Unit 1 Review
This worksheet should help you identify how we can use thermodynamics to understand
chemical reactions and builds off the previous work in the unit. It is intended for you to work
through it in order. (Don’t skip ahead.)
Mercury chloride is an incredible toxic compound, where even a small exposure (<1 g) can kill a
human in less than 24 hours. You are tasked with studying the dissolution of mercury chloride
in water.
HgCl2 (s) ßà ___ Hg2+ (aq) + ___ Cl- (aq)
Sº (J/mol K)
∆Hºf (kJ/mol)
HgCl2 (s)
146.0
-224.3
Hg2+(aq)
84.5
172.4
Cl- (aq)
56.5
-167.2
Use the table above to…
Calculate the standard change in entropy for the reaction.
Calculate the standard enthalpy of reaction.
Based on signs of enthalpy and entropy, do you expect the reaction to be spontaneous
or nonspontaneous at standard conditions (25 ºC)? Explain!
