The enthalpy of neutralization for the reaction of a strong acid with a strong base is −56 kJ/mol of water produced. How much energy will be released when 200.5 mL of 0.400 M HCl is mixed with 149.1 mL of 0.500 M NaOH?
200.5 mL x 0.400 M = 0.08020 mol HCl
149.1 mL x 0.500 M = 0.07455 mol NaOH
So you will produce 0.07455 mols H2O.
0.07455 mols H2O x 56 kJ/mol = ?