If water is pure enough and in a sufficiently smooth container,it can sometimes be “supercooled†so that it remains liquid for atime even when its temperature is lowered below its freezing point.(For this problem, you can use table 8.2 for heat capacities andmay assume that they do not change with temperature.)
(a) A beaker with 500 g liquid water initially at 10 ºC isplaced in a freezer at –15 ºC, where the liquid supercools until itis at the same temperature as the freezer. Calculate qH2O, and paycareful attention to its sign.
(b) The heat of fusion of ice at 0 ºC is 6.01 kJ/mol (Table8.3), but this number changes slightly with temperature. Calculatethe heat of fusion of ice at –15 ºC.
(c) The beaker of water from part (a) (now at –15 ºC) is takenout of the freezer and jostled, which triggers the water to freezerapidly (so quickly that the beaker is effectively insulated; noheat is transferred to or from the beaker’s surroundings). As theice forms, heat is given off and so the temperature of thewater/ice mixture rises until it reaches 0 ºC, at which point nomore ice forms. How much ice will form during this process?
