从溶液中析出晶体的途径很多,有的用减少溶液中溶剂的蒸发法,有的用降低溶液温度的冷却法,有的用既蒸发又冷却的方法。析出的晶体,有的不含结晶水,有的又含结晶水……计算类型繁多,解法不一,学生难以掌握。 There are many ways to precipitate crystals from solution. Some use evaporation methods that reduce the solvent in solution, others use cooling methods that lower the solution temperature, and some use methods that both evaporate and cool. Crystals precipitated, some without crystal water, and some with crystal water ... ... calculation of various types, different solutions, difficult for students to master.