What amount of heat (in kJ) is required to convert 16.9 g of an unknown solid (MM = 67.44 g/mol) at -15.4 C to a liquid at 42.7 C? (heat capacity of solid = 1.95 J/g. C; heat capacity of liquid = 1.18 J/g. C; AHfus = 5.72 kJ/mol; Tf = 28.3C)