某同学为了测定黄铜屑（由锌和铜形成的合金）样品组成。分四次取样品与稀硫酸反应，其实验数据记录如下表。.g9n.W)U0p0X1o;`0P0B
.g9n.W)U0p0X1o;`0P0B
试计算：.g9n.W)U0p0X1o;`0P0B
⑴第 次反应是锌和硫酸恰好完全反应。.g9n.W)U0p0X1o;`0P0B
⑵黄铜中锌的质量分数。.g9n.W)U0p0X1o;`0P0B
算式：提示5b(H/z;C0V-Q9]'n0_.g9n.W)U0p0X1o;`0P0B
答：黄铜屑中锌的质量分数为7~3{:d'~4n-I0E0u/[9e8Q+q。.g9n.W)U0p0X1o;`0P0B