题干

Cu与Zn的合金称为黄铜,有优良的导热性和耐腐蚀性,可用作各种仪器零件.某化学兴趣小组的同学为了测定某黄铜的组成,取10g该黄铜样品于烧杯中,向其中分5次加入相同溶质质量分数的稀硫酸,使之充分反应.每次所用稀硫酸的质量及剩余固体的质量记录于下表:


加入稀硫酸的质量(g)

充分反应后剩余固体的质量(g)

第1次

10

m

第2次

10

7.4

第3次

10

6.1

第4次

10

5.6

第5次

10

5.6

试回答下列问题:


(1)从以上数据可知,最后剩余的5.6g固体的成分是______;表格中,m=______

Cu


(2)黄铜样品中锌的质量分数为______

44%


(3)计算所用稀硫酸中硫酸的质量分数是多少?




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