The rate of reaction between sodium thiosulfate Na2S2O3 and hydrochloric acid HCl can be affected by various factors, including temperature, concentration, and the nature of the solvent. When the solvent is changed from water to an acetone-water mixture, the rate of reaction may be influenced in several ways.1. Solvent polarity: Acetone is less polar than water, and when mixed with water, the overall polarity of the solvent mixture decreases. Since both sodium thiosulfate and hydrochloric acid are polar, they may dissolve less readily in a less polar solvent, which could lead to a decrease in the rate of reaction.2. Dielectric constant: The dielectric constant of a solvent affects the rate of an ionic reaction. Water has a high dielectric constant, which helps to stabilize charged species and promote ionic reactions. Acetone has a lower dielectric constant than water, so mixing acetone with water will decrease the overall dielectric constant of the solvent mixture. This may result in a slower rate of reaction between sodium thiosulfate and hydrochloric acid.3. Viscosity: The viscosity of a solvent can also affect the rate of reaction. Generally, reactions occur more slowly in more viscous solvents because the movement of molecules is hindered. Acetone is less viscous than water, so mixing acetone with water may decrease the overall viscosity of the solvent mixture. This could potentially lead to an increase in the rate of reaction.4. Specific solvation effects: Some solvents can interact with reactants in ways that either promote or hinder the reaction. It is possible that the acetone-water mixture could have specific solvation effects on either sodium thiosulfate or hydrochloric acid that could influence the rate of reaction.In summary, changing the solvent from water to an acetone-water mixture can have complex effects on the rate of reaction between sodium thiosulfate and hydrochloric acid. The overall impact on the reaction rate will depend on the balance of these factors and the specific concentrations of the reactants and solvents used. To determine the exact effect on the reaction rate, experimental data would be needed.