• # question_answer 23) Calculate the enthalpy change on freezing of 1 mole of water at$10{}^\circ C$to ice at$-10{}^\circ C$. ${{\Delta }_{f}}H=6.03kJ\,mo{{l}^{-1}}at{{0}^{{}^\circ }}C.$ ${{C}_{p}}[{{H}_{2}}O(l)]=75.3\,\,J\,mo{{l}^{-1}}{{K}^{-1}}$ ${{C}_{p}}[{{H}_{2}}O(s)]=36.8\,\,J\,mo{{l}^{-1}}{{K}^{-1}}$

Step 1: Heat released in step 1 $q=-n{{C}_{p}}\Delta T$ Step 2: Heat released in freezing process $q=-n{{\Delta }_{freezing}}H$ $=-1\times 6.03=-6.03kJ$ $=-6030J$ Step 3: Heat released in the cooling ice $q=-n{{C}_{p}}\Delta T$ $=-1\times 6.03=-6.03kJ$ $=-6030J$ Total heat released: $q=-753-6030-368$ $=-7151J$