在实际应用中,我们常常要准确知道一定量的溶液里含有溶质的质量,即溶液的浓度.例如,在施用农药时,应较准确地知道一定量的药液里所含农药的量,若药液过浓,会毒害农作物;如果药液过稀,又不能有效地杀虫灭菌.在科学实验中,反应物的浓度不同,生成物可能也会不同.配置一定浓度溶液的方法有很多:(1)用固体溶于水来配置;(2)用一定质量的浓溶液加水稀释获 In practice, we often need to know precisely the amount of solute contained in a given amount of solution, ie, the concentration of the solution. For example, when pesticides are applied, the amount of pesticides contained in a given amount of liquid should be accurately known If the liquid medicine is too thick, it will poison the crops; if the liquid medicine is too thin, it can not be effectively sterilized. In scientific experiments, the concentrations of reactants may be different and the products may be different. There are many ways to dispose a certain concentration of solution : (1) with a solid dissolved in water to configure; (2) with a certain mass of concentrated solution diluted with water