Table 2.

The dissociation constant of m-nitroanilinium ion in deuterium oxide solution at 25 °C

Conc. of m-Nitroaniline: 3.98 × 10⁻⁴ M (3.61 × 10⁻⁴ mol/kg), 1 cm cell, 360 nm, D₁ = 0.038, D₂ = 0.568.

Conc. of DCla	D	$\text{log}\frac{D_2-D}{D-D_1}$	− log mD+	pK
0.000801	0.362	−0.197	3.180	2.983
.000984	.334	−.102	3.083	2.981
.001460	.272	+ .102	2.900	3.002
.001784	.244	+ .197	2.806	3.003
.002081	.225	+ .263	2.733	2.996
Average pK				2.993

^aIn moles per kilogram of solvent.