题型:问答题 简答题 ______ is particularly interested in the relationships between sentences and the contexts and situations in which they are used. 查看答案
题型:问答题 简答题 称取铜、锌混合物10克置于烧杯中,慢慢加入稀硫酸使其充分反应,直至固体质量不再减少为止,此时用去49克稀硫酸,剩余固体3.5克,(1)该混合物中铜的质量分数是多少?(2)所用的稀硫酸溶质的质量分数是多少?(3)反应后所得溶液中溶质的质量分数是多少? 查看答案