What would be the appropriate equilibrium temperature of a system obtained by adding 25.0 g of ice at 0 °C to 250.0 mL of "hot" (80 °C) coffee, assuming that the heat capacity and density of the coffee are the same as for pure water (4.18 J g-1 °C-1 and 0.997 g mL-1), and also assuming negligible heat transfer with the surroundings? [For water, ΔHfusion = 6.02 kJ/mol.]