Quantifying Electronic Polarizability and Concentration Sensitivity via Hollow Prism Refractometry

The determination of the refractive index of liquids is a fundamental technique in optical physics and chemical characterization. This study provides a comprehensive experimental analysis of the refractive indices of various aqueous solutions—specifically Sucrose, Glucose, Ammonium Sulphate, Tartaric Acid, Sodium Chloride (NaCl), and Sugar—across a concentration range of 5% to 40%. The measurements were conducted using a spectrometer in conjunction with a hollow prism, utilizing the principle of minimum deviation to calculate the mean refractive index of each sample. The results demonstrate that for several solutes, such as Sucrose and Glucose, the refractive index increases proportionally with concentration, reaching maximum values of 1.43964 and 1.43827 respectively at 40% concentration. In contrast, NaCl recorded a mean refractive index of 1.38407 at 40%, exhibiting non-linear behaviour across some concentration points. These findings underscore the sensitivity of optical density to solute mass and provide a quantitative framework for using refractometry in industrial applications, including food quality control, chemical concentration monitoring, and environmental salinity testing.

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