Table I.

Enthalpy and Heat Capacity Changes for Proton Dissociation from Buffers in 0.1M KCl at 25°C^a

Buffer	pK*	ΔH (kcal mol−1)	ΔCP (Cal mol−1 K−1)	δΔCP/ΔT (10−3 cal mol−1 K−2)
Acetate	4.62	0.117 ± 0.005	−30.5 ± 0.5
MES	6.07	3.709 ± 0.007	3.8 ± 0.5
Cacodylate	6.14	5.245 ± 0.005	−18.6 ± 0.5
Glycerol	6.26	4.949 ± 0.005	−42.8 ± 0.5	0.19 ± 0.09
PIPES	6.71	2.735 ± 0.010	4.5 ± 1.0
ACES	6.75	7.502 ± 0.012	−6.4 ± 1.0
Phosphate	6.81	1.223 ± 0.007	−44.7 ± 0.7	0.48 ± 0.05
BES	7.06	6.012 ± 0.017	0.5 ± 1.2
MOPS	7.09	5.212 ± 0.007	9.3 ± 0.7
Imidazole	7.09	8.739 ± 0.014	−3.8 ± 1.2
TES	7.42	7.820 ± 0.007	−7.9 ± 0.7
HEPES	7.45	5.018 ± 0.017	11.7 ± 1.2
EPPS	7.87	5.147 ± 0.012	13.4 ± 1.0
Triethanolamine	7.88	8.023 ± 0.010	11.5 ± 0.7
Tricine	8.00	7.636 ± 0.012	−10.7 ± 1.0
Bicine	8.22	6.461 ± 0.012	0.5 ± 1.0
TAPS	8.38	9.910 ± 0.014	5.5 ± 1.2
CAPS	10.39	11.594 ± 0.017	6.9 ± 1.4

^aData taken from Ref. 43.