To calculate the percentage change in the ionization constant of a weak acid when the temperature is increased, we can use the Van't Hoff equation. The Van't Hoff equation relates the change in temperature to the change in the equilibrium constant K of a reaction:ln K2/K1 = -H/R * 1/T2 - 1/T1 Where:- K1 and K2 are the ionization constants at temperatures T1 and T2, respectively- H is the standard enthalpy change of the reaction- R is the gas constant 8.314 J/molK - T1 and T2 are the initial and final temperatures in Kelvin, respectivelyFirst, we need to convert the temperatures from Celsius to Kelvin:T1 = 25C + 273.15 = 298.15 KT2 = 35C + 273.15 = 308.15 KSince we are given that the Van't Hoff factor is constant and equal to 1, we can assume that the ratio of the ionization constants K2/K1 remains constant. Therefore, we can rewrite the Van't Hoff equation as:ln K2/K1 = -H/R * 1/308.15 - 1/298.15 To find the percentage change in the ionization constant, we need to find the ratio K2/K1. We can rearrange the Van't Hoff equation to solve for this ratio:K2/K1 = exp -H/R * 1/308.15 - 1/298.15 However, we are not given the value of H, the standard enthalpy change of the reaction. Without this value, we cannot calculate the exact percentage change in the ionization constant.In general, the ionization constant of a weak acid will increase with increasing temperature, as the reaction becomes more favorable at higher temperatures. The exact percentage change, however, depends on the specific weak acid and its enthalpy change.