Complex
(HL)
t°C

K. cal. mol-1

K. cal. mol-1
30 40 50 - ΔG°30 -ΔH°30 -ΔS°30
logk1 logk2 logk1 logk2 logk1 logk2 - ΔG°1 - ΔG°2 - ΔH°1 - ΔH°2 ΔS°1 ΔS°2
Co(II) 10.09 10.56 9.79 10.4 9.55 10.2 13.9903 14.6419 0.120863 0.0803863 0.0457736 0.0480579
Cd(II) 9.88 10.99 9.69 10.6 9.52 10.1 13.6991 15.2381 0.080528 0.198704 0.0449457 0.0496351
Ni(II) 10.18 10.57 9.8 10.32 9.55 10.11 14.115 14.6558 0.141149 0.10293 0.0461185 0.0480296
Zn(II) 9.21 9.69 8.93 9.31 8.61 9 12.7701 13.4356 0.134038 0.15442 0.0417032 0.0438324
Fe(III) 7.41 8.4 6.9 8.1 6.5 7.9 10.2743 11.647 0.203699 0.112015 0.0332363 0.0380692
Mn(II) 9.91 10.61 7.96 10.47 6.7 10.3 13.7407 14.7113 0.719272 0.0692309 0.0429749 0.0483235
pka 10.751   10.544   10.371   14.9068   0.0850294   0.0489166  
Type of complex ΔGoΔS° ΔH° and ΔS°
inner sphere complex Large negative Large positive
outer sphere complex Small negative Small positive
Table 1: Thermodynamics functions and stepwise formation constants of 1:1 and 1:2 metal complexes at 30, 40, and 50°C in 75% ethanol-water.