AN IMPROVED METHOD OF ISOMOLAR SERIES BY DUAL-WAVELENGTH SPECTROPHOTOMETRY

An improved method of isomolar series for determining the composition of an aqueous binary spectrophotometric system is proposed. It is base d on the determination by dual-wavelength spectrophotometry of the equ ilibrium concentration of the chromogenic agent L added in excess, the absorbance of which has been found to be a linear function of n/m, th e composition index of the reaction product M(m)L(n) in the system, He nce it is a direct and reliable method, applicable also to systems in which the absorption spectra of L and M(m)L(n) overlap and can be reso lved by instrumental masking.