A solid metallic block weighing 5 kg has an initial temperature of 500°C. 40 kg of water initially at 25°C is contained in a perfectly insulated tank. The metallic block is brought into contact with water. Both of them come to equilibrium. Specific heat of block material is 0.4 kJ.kg -1 .K -1 . Ignoring the effect of expansion and contraction and also the heat capacity to tank, the total entropy change in kJ.kg -1 .K -1 is