Heat of precipitation (Find the heat change)

Calculate the heat change when 200 cm³ of 0.5 mol dm^-3 calcium chloride, CaCl₂  solution  is added to 200 cm³ of 0.5 mol dm^-3 sodium carbonate, Na₂CO₃ solution if the heat of precipitation of calcium carbonate, CaCO₃ is  +12.6 kJ mol^-1

[ Specific heat capacity of solution : 4.2 J g^{-1 0}C^-1 . Density of solution : 1 g cm^-3 ]

(ans: 1.26 kJ)