Posted by Jordan on .
Calculate the heat energy released when 29.7 g of liquid mercury at 25.00 °C is converted to solid mercury at its melting point.
Constants for mercury at 1 atm: Heat capacity of Hg (l) 28.0 J/Mol*K, Melting pt 234.32 k, and enthalpy of fusion 2.29 kg/mol
q1 = heat released in cooling Hg from +25C to its melting point which is -83.3C.
q1 = mass Hg x specific heat Hg x (Tfinal-Tinitial)
Tfinal is -83.3. Ti is 25C.
q2 = heat released on freezing Hg.
q2 = mass Hg x heat fusion..
Total q = q1 + q2.
You have given specific heat in kJ/mol and J/mol; therefore, you must convert grams Hg to mols Hg.mol = grams/molar mass.