انا جد مضطرة عالسؤال

Question

a quantity 2*10^2 ml of 0.862 M HCl ia mixed with 2.00 O 10^2 mL of 0.431 M Ba(OH)2 ia a constant-pressure calorimeter of negligible heat capacity. The initial temperature of the HCl and Ba(OH)2 solution is the same at 20.48C , for the process H+(aq) + OH-(aq)  --------------> H2O (l) the heat of neutralization is -56.2 kj\mol. what is the final temperature of the mixed solution ??‏