To determine the new equilibrium concentration of the complex ion, we first need to write the balanced chemical equation for the reaction:Fe3+ aq + SCN- aq FeSCN2+ aq Next, we need to set up an ICE Initial, Change, Equilibrium table to keep track of the changes in concentrations during the reaction:...........[Fe3+]....[SCN-]....[FeSCN2+]Initial....0.025 M...0.015 M...0.007 MChange....-x........-x.........+xEquilibrium 0.025-x...0.015-x...0.007+xNow, we can write the expression for the equilibrium constant K for the reaction:K = [FeSCN2+] / [Fe3+] * [SCN-] At the initial temperature of 25C, the equilibrium constant K is given as 0.056. We can plug in the equilibrium concentrations from the ICE table into the K expression:0.056 = 0.007+x / 0.025-x * 0.015-x To solve for x, we can make an assumption that x is small compared to the initial concentrations, so we can approximate that 0.025-x 0.025 and 0.015-x 0.015. This simplifies the equation to:0.056 = 0.007+x / 0.025 * 0.015 Now, we can solve for x:x = 0.056 * 0.025 * 0.015 - 0.007x 0.0003Since the temperature is increased by 10C, the equilibrium constant will change. However, without knowing the enthalpy change H for the reaction, we cannot determine the new equilibrium constant at the higher temperature using the Van't Hoff equation. Therefore, we cannot determine the new equilibrium concentrations of the complex ion at the increased temperature.