To calculate the standard enthalpy change for the reaction, we first need to determine the amount of heat released or absorbed by the reaction. Since the reaction is exothermic, the heat released by the reaction will be absorbed by the solution.1. Calculate the moles of HCl and NaOH:moles of HCl = volume of HCl x concentration of HCl = 25.0 mL x 0.100 mol/L = 0.00250 molmoles of NaOH = volume of NaOH x concentration of NaOH = 25.0 mL x 0.100 mol/L = 0.00250 mol2. Determine the limiting reactant:Since the moles of HCl and NaOH are equal, the reaction will go to completion, and both reactants will be completely consumed.3. Calculate the heat released by the reaction:The heat released by the reaction q can be calculated using the formula q = mcT, where m is the mass of the solution, c is the specific heat capacity, and T is the change in temperature.First, we need to find the mass of the solution:mass of solution = volume of solution x density of solution = 25.0 mL + 25.0 mL x 1.00 g/mL = 50.0 gNext, we need to find the change in temperature T . Since the reaction has reached equilibrium, we can assume that the final temperature of the solution is the same as the initial temperature 25C . Therefore, T = 0.Now, we can calculate the heat released by the reaction:q = mcT = 50.0 g x 4.18 J/gC x 0C = 0 JSince the heat released by the reaction is 0 J, the standard enthalpy change for the reaction is also 0 J/mol. However, this result is not accurate because the assumption that T = 0 is not valid. In reality, the reaction between HCl and NaOH is exothermic, and the temperature of the solution will increase. To determine the actual standard enthalpy change for the reaction, we would need to know the final temperature of the solution or the enthalpy of reaction for the formation of NaCl and H2O.