Page 265 - Thermodynamics of Biochemical Reactions

Chemical Equilibrium in One Phase Systems 265

TableForml{dGrxa,dGrxb,dGrxc,dGrxd,dGrxe,dGrxf}rTableHeadings-
>C{"dGrxan, ildGrxblm, lldGrxcll, ndGrxd", i~dGrxei~,ildGrxfil}, {0,0.10,0.25}}]
0 0.1 0.25
dGrxa 22.65 20.2017 19.4113
dGrxb 25.99 21.0935 19.5126

dGrxc -3.34 -0.891743 -0.101311
dGrxd 65.29 62.8417 62.0513
dGrxe 29.53 25.8576 24.672
dGrxf 79.26 75.5876 74.402

Table 2 Equilibrium constants at 298.15 K

TableForml{krxa,krxb,krxc,krxd,krxe,krxf},TableHeadings-
> { { **krxa", lmkrxbllr ilkrxc", "krxdn, "krxe", "krxf "1 (0,O. 10,O. 25) > 1
0 0.1 0.25
krxa 0.000107625 0.000288953 0.00039747

krxb 0.0000279753 0.000201652 0.000381554
krxc 3.84715 1.43293 1.04171
-12 -12 -11
krxd 3.64546 10 9.78736 10 1.3463 10
-6
krxe 6.70807 10 0.0000295099 0.0000476083
-14 -14 -14
krxf 1.30115 10 5.72398 10 9.23451 10

These values agree with R. A. Alberty, Arch. Biochem. Biophys. 307, 8-14 (1993).

3.4 Plot the acid dissociation constant of acetic acid from 0 OC to 50 OC given that at 298.15 K, AfGo = 27.14 kJ mol-',
Af Ho = -0.39 kJ mol-', and Af Cp"= -155 J K-lmol-'. Assume zero ionic strength.

AfF = (Af H" - AfGo )/T

deltaS=(-390-27140)/298.15
-92.3361

46.906 298.15
-11.1059 + ~ + 18.6421 (1 - ___ - Log [O .00335402 tl 1
t t
plot [ink, { t, 273.15,323.15} .hesOrigin->{270, -11.02) ,hesLabel->{ "T/K", "AG"11 i