Chapter 4 from S&A: 23, 24, 31, 41, 44, 45, 46

as well as:

In class we derived a expression for the entropy in terms of T and V that was valid for any fluid,

dS = (C_v/T)dT + (alpha/kappa)dV .

Using a similar procedure, derive the analogous expression in terms of T and P. Compare this result with the expression specific to an ideal gas.

Hints/comments:

4.23: First find the molality of the solutions with given wt% of ZnCl₂. Note that wt% = [ wt/(wt+1000 g) ] x 100%, where wt is the weight of solute in 1000 g of solvent. You'll also need the total volume of solution with total mass = 1000 g + wt. Utilitze the density for this. Finally, the partial molar volume is defined by Eq. 4.50 in the text which requires the derivative of volume vs. molality. Hence, fit the V vs. m values to a polynomial or interpolate and then take the derivative at the molality specified.

4.44: this is an isothermal process

4.46: consider the reversible cycle: H₂O(l,-10C,1 bar) -> H₂O(l,-10C,286.5 Pa) -> H₂O(g,-10C,286.5 Pa) -> H₂O(g,-10C,260 Pa) ->H₂O(s,-10C,260 Pa) -> H₂O(s,-10C,1 bar)

Note: please work these problems without the help of a solutions manual! Otherwise you might see a problem set like #6 again....

Some numerical answers not given in the back of the book:

31) -0.0252 J K^-1 mol^-1 (confirmed)

41) 3100 J/mol, -40.689 J/mol, -37.6 kJ/mol, -40.69 kJ/mol, 3.10 kJ/mol, -109.0 J K^-1 mol^-1, 0 kJ/mol (confirmed, obviously in no particular order)

44) 0, -13.38 J K^-1 mol^-1, 4993 J/mol (confirmed)

45) 33.35 kJ/mol, 86.80 J K^-1 mol^-1, 0.0 (confirmed)

46) -212.1 J/mol (confirmed)