Table IV.

Solubilities and Estimated Thermodynamic Properties of Procaine Salts

	Ideal solubility (x ideal)	Measured solubility (x meas)	ln γ	ΔHfus (kJ/mol) at 298 K	ΔHmix (kJ/mol)
Phosphate	0.165	0.010	2.8	28.3	−2.7
Citrate	0.198	0.016	2.5	38.6	0.5
Besylate	0.473	0.012	3.7	31.5	5.6
Oxalate	0.085	1.2 × 10−3	4.2	41.3	6.3
Bisulfate	0.478	0.128	1.3	33.0	−13.8
Esylate	0.557	0.100	1.7	27.8	−7.6
Napsylate	0.230	4.7 × 10−4	6.2	27.9	8.0
Tosylate	0.159	1.3 × 10−3	4.8	35.1	1.6
Formate	0.754	0.150	1.6	32.2	−13.0
Mesylate	0.671	0.145	1.5	23.0	−0.7
HCl	0.276	0.108	0.9	26.8	5.7