(a) Making use of the fact that Eq. (6.20) is an exact differential expression, show that: (@Cp/aP)r = -T(a2v/aT2)p What is the result of application of this equation to an ideal gas? (b) Heat capacities Cy and Cp are defined as temperature derivatives respectively of U and H. Because these properties are related, one expects the heat capacities also to be related. Show that the general expression connecting Cp to Cy is: C, - Cy +7 (), (), de, Cp = Cy +T aT Show that Eq. (B) of Ex. 6.2 is another form of this expression.