Adding a catalyst, such as platinum, to the redox reaction between iodine and thiosulfate will not change the equilibrium position or the equilibrium constant K of the reaction. Catalysts work by lowering the activation energy of a reaction, which increases the reaction rate, but they do not affect the thermodynamics of the reaction. Therefore, the equilibrium constant will remain the same.The redox reaction between iodine I2 and thiosulfate S2O3^2- can be represented as follows:2 S2O3^2- aq + I2 aq S4O6^2- aq + 2 I^- aq The observed changes in the reaction rate and yield due to the addition of a platinum catalyst can be explained as follows:1. Increased reaction rate: The platinum catalyst provides an alternative reaction pathway with a lower activation energy. This allows more reactant molecules to have enough energy to undergo the reaction, resulting in an increased reaction rate.2. Faster attainment of equilibrium: Since the reaction rate is increased, the system will reach equilibrium more quickly. However, the final equilibrium position and yield will not be affected by the presence of the catalyst.In summary, adding a platinum catalyst to the redox reaction between iodine and thiosulfate will increase the reaction rate and allow the system to reach equilibrium more quickly, but it will not change the equilibrium position or the equilibrium constant.