Question

In an adiabatic calorimetry experiment, 100 mL of 0.500 M HCl was added to 100 mL 0.500 M NaOH to produce 200 mL 0.25 M NaCl. A temperature increase of 3.38 °C was measured. Calculate the heat of reaction associated with this process at 25 °C from the data in Table 1, for one mole of reactant and for the reaction conditions used. Use this value to calculate the heat capacity of the system, Ctotal.

Answer 1

What's in Table I?
Erxn = mass x specific heat x dT.
If you assume density of the solution is the same as H2O you use 200 g for mass; otherwise if Table I contains the density use that to calculate mass of the 200 mL solution.
Probably Table 1 contains specific heat; use that or 4.184 J/g*C and calculate E/rxn = E/0.25 mol and convert that to E/1 mol.
Ctotal = E/T