Download Fundamental Equations of Thermodynamics - Homework 6 | Chem 331 and more Assignments Physical Chemistry in PDF only on Docsity! Chem 331, Homework #6 (Fundamental Eqns. of Thermo)
(Due Mon., Oct. 15th, 2007 at beginning of class)
(1) Calculate AS? and AGP at 298.15 K for the following reactions. The latter can utilize the AH?
, values from homework #4.
(a) 4NH3(g) + 6NO(g) > 5No(g) + 6H20(g)
(b) 2NO(g) + Oa(g) > 2NO2(g)
(c) TiCl4() + 2H,00) > TiO,(s) + 4HCI(g)
ou oH oH 0G
2) Show that |2%) =(2) ana (2%) 2/22).
” ow at (55), (a), (#), (=),
(3) (a) Given that S = (7,P), derive an expression for dS in terms of T and P that is valid for any
fluid.
(b) The coefficient of thermal expansion B of Fe(s) at 25°C is 355 x 10°’ Kl. What is the change
in molar entropy of iron when the pressure is raised from 1 to 1000 bar? (The density of iron at
25°C is 7.86 g om”) oh 25°C.
(4) In the thermodynamics of elastic materials, d4 =—SdT + fal, where fis the force exerted and L
is the stretching displacement. Derive the appropriate Maxwell relation and then use this to
obtain an expression for AS for isothermal stretching.
(5) Steam is compressed reversibly to liquid water at the boiling point (100°C) and 1 atm. The heat
of vaporization of water at 100°C and 1.01325 bar is 2258 J g. Calculate w per mole and g per
mole and each of the thermodynamic quantities AH, AU, AG, AA, and AS . You can assume
that the volume of the liquid is negligible compared to that of the gas.
(6) When a liquid is compressed its Gibbs energy is increased. The increase in molar Gibbs energy
can be calculated using [¥) =V. What is the change in molar Gibbs energy for liquid water
T
(p=10g om) when it is compressed from 1 to 1000 bar (assuming V is constant)?
(7) Starting with the fundamental equation for dU, derive the relation (2) = V(kP — BT)
T
@. s=f£ae)
, _ jas os
(a) as= (32) ar (Se) ae
Von
dS Byes fn cost P ) te 2 Colt
ase eat 4s. . fe
OL AT P T
as Cc
> ( #3) = Ar
Sa He 22 cose, (sr > -(#)
T Pr
Via He Maxwell cele an AG
ne oy (FF) = “Fh mas
(3b). Fax constad Tyo. AS > VAP
© assamig Vie & ace wulepindete of
AS = -V@AP o MS =-V BAP Sa mole,
rene SS.847 a ( pe NF
=o
N= F * FRG * eh [Oden
y
31082. x07” om med
. ; AS = - (atosaxi0° (ase x10 2") (000 Dy c10? ke
= -0.0262 sx"!
_ dh > {
