Table 1.

Summary of results

Determination number	Potassium hydrogen phthalatea	Potassium hydrogen phthalateb	Benzoic acida	Benzoic acidb	Hydrochloric acida c	Adipic acida d	Adipic acidb e	Sodium carbonatea
	assay	assay	assay	assay	assay	assay	assay	assay
	%	%	%	%	%	%	%	%
1	99.976	99.979	99.985	99.991	99.982	99.935	99.985	99.909
2	99.980	99.976	99.991	99.993	100.004	99.937	99.987	99.901
3	99.978	99.981	99.989	99.996	100.014	99.937	99.980	99.915
4	99.970	99.976	100.001	99.991	100.003	99.947	99.981	99.910
5	99.974	99.974	99.985	99.986	100.002	99.942	99.989	99.920
6	……………………………………	……………………………………	……………………………………	99.998	99.999	99.955	……………………………………	……………………………………
7	……………………………………	……………………………………	……………………………………	……………………………………	99.990	99.951	……………………………………	……………………………………
8	……………………………………	……………………………………	……………………………………	……………………………………	……………………………………	99.948	……………………………………	……………………………………
Mean	99.976	99.977	99.990	99.994	99.999	99.945	99.984	99.911
Standard deviation	0.004	0.003	0.006	0.004	0.010	0.007	0.004	0.007

^aTimed by electric clock.

^bTimed by time interval meter.

^cAssay based on calculated acidity by the pressure-distillation method.

^dOnce recrystallized from melt.

^eTwice recrystallized from melt.