Freon -12, CCl2F2, is used as refrigerant. It’s heat of vaporization is 289J/g . What mass of
Freon-12 must evaporate in order to freeze 500 g of water initially at 20 OC (The heat of fusion
of water is 334 J/g : the heat capacity of water per gram is 4.18 J/g-K)