Upon completion, the Draught of Peace needs to be cooled to a temperature of 63°F before anyone can drink it. How much ice at a temperature of -5°F would Harry need to add to the potion to cool the system to this temperature once he takes it off the fire? Assume the potion has a mass of 5.34 kg, the specific heat of the potion is 3483 J/kg°C, the mass of the cauldron is 8.3 kg, pewter has a specific heat of 220 J/kg°C, the latent heat of fusion for water is 3.34 x 105 J/kg, the specific heat of ice is 2090 J/kg°C, and the specific heat of water is 4186 J/kg°C.
