[Beetle]

125 mL of 0.450 M HCl is mixed with 176 mL of 0.320 M NaOH in a constant-pressure calorimeter of negligible heat capacity.
What is the heat change of the solution given the heat of neutralization for the reaction below is -56.2 kJ?
H+(aq) + OH-(aq) → H2O(l)
(+/-) 1 2J
The initial temperature of each solution is 19.7 °C.
(Assume the the solutions have a density of 1.000 g/ml and the specific heat is 4.184 J/g · °C)
What is the final temperature of the solution?  °C

[Beetle]

what is the first step to trying to find the solution to this problem?