72 
A problem in which the Gibbs phase rule must be used to determine the number of degrees of freedom. The key is correctly counting phases (easier) and components (harder). This problem has no complications; it is straightforward. 
74 
Another problem based on the Gibbs phase rule. This problem explores some of the complications
of counting components. The simple
rule about being able to count components by working out how many bottles
must be opened to make the system works, but writing down the material
requested by Levine is a good review of CHE 226 material. 
75 
A third problem based on the Gibbs phase rule. Part (e) is tricky It is an example of a situation in which the shortcut to counting components does not work; the correct number of components can only be obtained by writing down all the chemicals present and then finding all the relationships between them. The point of this problem is to show that counting independent components is occasionally difficult. 
710 
Another T/F problem. This one concerns phase equilibria. A triple point is
a pressure, temperature combination at which three phases (e.g., solid/liquid/gas or
solid1/solid2/liquid) are in equilibrium.
If c=1 then f=0 at a triple point. 
711 
A problem based on the common substance water. A number of sets of temperatures and pressures are given. Which phase of water is stable (i.e., has the lowest chemical potential = molar free energy) in each case? 
713 
A basic problem involving the vaporization equilibrium of water. 
716 
A simple thought problem that requires a little knowledge of chemistry. The quantities D_{vap}H^{o} and D_{vap}U^{o} measure the strength of intermolecular attractions in the liquid (i.e., in a condensed) phase. The stronger the intermolecular attractions the larger D_{vap}H^{o} and D_{vap}U^{o}. Attractions increase with the total number of electrons (which is why the boiling point is correlated with molar mass) and with the number of hydrogen bonds. 


721 
Short, but very important T/F problem.

722 
Calculate the vapor pressure of an organic liquid given the normal boiling point and D_{vap}H^{o} at the normal boiling point using the ClausiusClapeyron equation. Remember that D_{trans}S = D_{trans}H/T_{trans}.because D_{trans}G = 0 if the two phases are in equilibrium. 
723 
Standard problem: Estimate the pressure that must be applied to lower the
melting point of water n deg C. 
760 
A small thought problem designed to help with understanding of chemical potential. Vapor pressure is a direct measure of chemical potential. 
765 
A very short question about the properties of the triple point. 


737 
Calculation of the transition pressure for graphite/diamond at 1000 K
rather than at 298 K. The increased
temperature is desirable because it means the transition will take place
faster. 
738 
At what temperature are two solid forms of tin at equilibrium? The difference in entropy between the two forms is more important that the difference in density. 
739 
How does including the difference in the compressibilities of graphite and diamond affect the estimated transition pressure? 

