Table 4.

Dissociation constants in aqueous and deuterium oxide solutions at 25 °C determined by the spectrophotometric method

	pK (in H2O)	pK (in D2O)	ΔpK
o-Nitroanilinium ion	−0.263 [20]	0.305	0.568
m-Nitroanilinium ion	2.460 [17]	2.993	.533
4-Chloro-2,6-dinitrophenol	2.969 [17]	3.482	.513