Different polar solvents have been used to record and analyze the electronic absorption spectra of 4-NHPBS (E)-4-((2-hydroxynaphthalen-1-yl)diazenyl)-N-(pyrimidin-2- yl)benzenesulfinamide. The coefficients of determination for regression and correlation were computed using multiple linear regression methods. The empirical Kamlet-Taft solvent parameters were used as a starting point for these regressions, based on an equation linking the absorption bands’ wavenumber maxima (vmax). Dipalanty/polarizability, hydrogen-bond donor acidity, and hydrogen-bond receptor basicity are all properties of solvents. This analysis’s regression fits provide a means of assessing the relative contribution of different types of interaction to overall spectral changes in the solution. The resulting hands are impacted by both specific and non-specific salute-solvent interactions, as shown by the dependency of Vmax on the solvent parameters. The pKa and the isosbestic point of the reagent 4-HNPBS were determined using UV-Vis spectrophotometry. The alcoholic solution of 4-HNPBS was mixed with water in a ratio of 0.1:4.9 of absolute ethanol to water. This ratio does not alter the maximum absorption. It shows the pH effect on the 4-HNPBS in the range of 1.0 to 12, and 530 shows the isosbestic point for the 4-HNPBS. Depending on the medium’s acidity, the absorbance-pH plot at certain wavelengths displays a Z-shape curve with two inflections corresponding to pKa1, pKa2, and pK3.