Thermodynamics and Chemistry

CHAPTER 11 REACTIONS AND OTHER CHEMICAL PROCESSES

PROBLEMS 361

Table 11.3 Data for Problem 11. 7. The values of intensive properties are

for a temperature of298:15K and a pressure of 30 bar unless otherwise

stated. Subscripts: A = H 2 O, B = O 2 , C = CO 2.

Properties of the bomb vessel:

internal volume....................... 350:0cm^3

mass ofn-hexane placed in bomb....... 0:6741g

mass of water placed in bomb.......... 1:0016g

Properties of liquidn-hexane:

molar mass........................... MD86:177g mol^1

density............................... D0:6548g cm^3

cubic expansion coefficient............. D1:378 10 ^3 K^1

Properties of liquid H 2 O:

molar mass........................... MD18:0153g mol^1

density............................... D0:9970g cm^3

cubic expansion coefficient............. D2:59 10 ^4 K^1

standard molar energy of vaporization.. .ÅvapUD41:53kJ mol^1

Second virial coefficients,298:15K:

BAA.................................  1158 cm^3 mol^1

BBB................................. . 16 cm^3 mol^1

dBBB=dT............................ 0:21cm^3 K^1 mol^1

BCC................................. . 127 cm^3 mol^1

dBCC=dT............................ 0:97cm^3 K^1 mol^1

BAB.................................  40 cm^3 mol^1

BAC................................. . 214 cm^3 mol^1

BBC................................. .43:7cm^3 mol^1

dBBC=dT............................ 0:4cm^3 K^1 mol^1

Henry’s law constants at 1 bar (solvent = H 2 O):

O 2.................................. .km;BD 796 bar kg mol^1

CO 2................................. km;CD29:7bar kg mol^1

Partial molar volumes of solutes in water:

O 2.................................. .VB^1 D 31 cm^3 mol^1

CO 2................................. VC^1 D 33 cm^3 mol^1

Standard molar energies of solution (solvent = H 2 O):

O 2.................................. .ÅsolUD9:7kJ mol^1

CO 2................................. ÅsolUD17:3kJ mol^1

11.7 This 16-part problem illustrates the use of experimental data from bomb calorimetry and other
sources, combined with thermodynamic relations derived in this and earlier chapters, to eval-
uate the standard molar combustion enthalpy of a liquid hydrocarbon. The substance under
investigation isn-hexane, and the combustion reaction in the bomb vessel is

C 6 H 14 .l/C^192 O 2 .g/!6 CO 2 .g/C7 H 2 O.l/

Assume that the sample is placed in a glass ampoule that shatters at ignition. Data needed for

this problem are collected in Table11.3.

States 1 and 2 referred to in this problem are the initial and final states of the isothermal bomb

process. The temperature is the reference temperature of298:15K.