A stream of 12 kg·s⁻¹ of Cu(NO₃)₂⋅6H₂O and a stream of 15 kg·s⁻¹ of water, both at 25°C, are fed to a tank where mixing takes place. The resulting solution passes through a heat exchanger that adjusts its temperature to 25°C. What is the rate of heat transfer in the exchanger?
∙ For Cu (NO₃)₂ , ΔH^°_{f 298}  = −302.9 kJ.
∙ For Cu (NO₃)₂  ⋅ 6H₂O, ΔH^°_{f 298} = − 2110.8 kJ.
∙ The heat of solution of 1 mol of Cu(NO₃)₂ in water at 25°C is −47.84 kJ, independent of ñ for the concentrations of interest here.