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一、溶液中溶质的质量分数模型构建例1:已知25%氨水的密度为0.91g/cm~3,5%氨水的密度为0.98g/cm~3,若将上述两溶液等体积混合,所得氨水溶液的质量分数( )A.等于15%B.大于15%C.小于15%D.无法确定解题策略分析:常规解法一般如下,设所取溶液的体积为VmL,则混合后溶液的质量分数为[25%·0.91V+5%·0.98V]/(0.91V+0.98V)=14.63%<15%。解
First, the mass fraction of solutes in the solution Construction Example 1: Known 25% ammonia water density of 0.91g / cm ~ 3,5% ammonia water density of 0.98g / cm ~ 3, if the above two solutions were mixed by equal volume, The resulting ammonia solution mass fraction () A. Equal to 15% B. More than 15% C. Less than 15% D. Can not determine the problem-solving Strategy Analysis: General solution is generally as follows, the volume of the solution taken VmL, the mixed solution The mass fraction was [25% · 0.91V + 5% · 0.98V] / (0.91V + 0.98V) = 14.63% <15%. solution