To calculate the standard enthalpy change for the reaction, we first need to determine the heat released or absorbed during the reaction, and then divide it by the moles of the limiting reactant.The balanced chemical equation for the reaction is:HCl aq + NaOH aq NaCl aq + H2O l First, we need to determine the limiting reactant. We can do this by calculating the moles of each reactant:moles of HCl = concentration volume = 0.25 M 0.050 L = 0.0125 molmoles of NaOH = concentration volume = 0.10 M 0.050 L = 0.005 molSince there are fewer moles of NaOH, it is the limiting reactant.Next, we need to determine the heat released or absorbed during the reaction. We can do this using the heat capacity of the solution and the temperature change. However, the temperature change is not provided in the problem. We can assume that the reaction is exothermic and the temperature change is negative, but we cannot calculate the standard enthalpy change without the temperature change.If the temperature change was provided, we could calculate the heat released or absorbed using the following formula:q = heat capacity mass of the solution temperature changeThen, we could calculate the standard enthalpy change by dividing the heat released or absorbed by the moles of the limiting reactant:H = q / moles of limiting reactantHowever, without the temperature change, we cannot complete this calculation.