A reaction is peformed in which 50 ml of .400M silver nitrate and 75 ml of .100M hydrochloric acid are mixed together. The initial temperature of the solutionn was 25 C and the final temperature was 27.2 C. What is the enthalpy, in kj/mol, for the formation of the precipitate (silver chloride)? The volume of the final solution was 125 ml, and it had the density of 1.00g/ml. The specific heat of solution is 4.18 J/g*C.

Answer 1

q = heat generated = [mass H2O x specific heat H2O x (Tfinal-Tinitial)]

That gives you delta H for the reaction.
q/mol AgCl = delta H/mol
Note: It appears HCl is the limiting reagent.