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浓度问题实际上就是百分比问题,其基本数量关系有以下几种:1.溶质的质量÷溶液的质量=浓度2.溶液的质量×浓度=溶质的质量3.溶液的质量×(1-浓度)=溶剂的质量4.溶质的质量÷浓度=溶液的质量5.溶剂的质量÷(1-浓度)=溶液的质量解决此类问题,除了要灵活运用以上数量关系外,还要善于发现题目中的不变量,借助不变量巧妙解决浓度问题。【例1】将浓度为25%的60千克盐水,与浓度为20%的40千克盐水混合在一起,混合后盐水的浓度是多少?【分析与解】将两种浓度不同的盐水混合在一起,要求混合后盐水的浓度,必须知道混合后盐的总质量和盐水的总质
Concentration problem is actually a matter of percentage, the basic relationship between the number of the following: 1 solute quality ÷ solution mass = concentration 2 solution mass × concentration = solute mass 3 mass of the solution × (1 - concentration) = Mass of solvent 4. mass of solute ÷ concentration = mass of solution 5. mass of solvent ÷ (1-concentration) = mass of solution To solve such problems, in addition to being flexible in using the above quantities, Of the invariants, with the help of invariants to solve the concentration problem. 【Example 1】 The concentration of 25% of 60 kg of brine, and 20% concentration of 40 kg of salt mixed together, the concentration of salt after mixing What is the 【Analysis and Solutions】 Two different concentrations of brine mixed together , Requires the concentration of brine after mixing, it is necessary to know the total mass of salt after mixing and the total mass of brine