Hydration is a fundamental process that governs the structural and energetic properties of aqueous electrolyte solutions. In this study, a refractometric method based on the Lorentz–Lorenz equation was employed to determine the total hydration numbers of sodium acetate, zinc acetate, and sodium citrate. The analysis yielded hydration num-bers of 6.3, 10.5, and 20.3, respectively. These results confirm that ion charge, ionic size, and molecular architecture significantly influence hydration behavior. Specifically, the higher hydration number of zinc acetate is attributed to the strong electric field of the divalent Zn²⁺ ion, while sodium citrate’s high value highlights the collective impact of multiple functional groups. Ultimately, this work demonstrates that refractometry is an effective tool for investigating the complex interplay of electrostatic and structural fac-tors in hydration phenomena.