一、提纯将混合物中的某些组分用物理的或者化学的方法除去而得到纯物质的方法叫提纯。提纯的方法有:1.过滤法:易溶和难溶于水的组分形成的混合物适合用过滤法。如CaCO3中混有Na2CO3。2.结晶法:都易溶于水的组分形成的混合物若各组分物质随温度变化溶解度有较大差异时,适合用结晶法。如KNO3中混有NaCl。3.沉淀法:加入某种试剂后可将某一组分(或杂质)结 First, the purification of the mixture of certain components of the physical or chemical methods to remove pure substance obtained by the method called purification. Purification methods are: 1. Filtration method: a mixture of easily soluble and poorly water-soluble components suitable for filtration. Such as CaCO3 mixed with Na2CO3.2. Crystallization method: All easily soluble in water The composition of the mixture If the components of the material with a large temperature solubility change, suitable for crystallization. Such as KNO3 mixed with NaCl. 3. Precipitation: adding a certain reagent can be a component (or impurity) junction