6. A solution was prepared by dissolving 7.45 g of KCI in 200 g of H20 in a calorimeter with a water equivalent of 25g. The temperature of the water had reduced from 28℃ to 25℃. △H for dissolving KCl in water is (Specific heat capacity of water is 4.2 J/K/g) (A) 2.520 hJ/mol, (B) 2.835 k/mol, (C) 20.60 kJ/mol, (D) 25.20 kJ/mol, (E) 28.35 kJ/mol.