杭州交通信息网滨海县八滩中学贴吧:一化学题.快
来源：百度文库 编辑：杭州交通信息网 时间：2024/04/28 03:53:39
在托盘天平两边各放一个烧杯平衡．再向两个烧杯中加人相同质量的稀硫酸，向左边投入13克锌片，要保持天平仍然平衡，需向右盘加入多少克铁？
楼上错了
要保持天平仍然平衡，左右两侧实际增重要相等.
左:
Zn + H2SO4=ZnSO4 + H2↑ 实际增重
65`````````````````````2``````````65-2
13````````````````````````````````````X
X=12.6g
右:
Fe + H2SO4=FeSO4 + H2↑ 实际增重
56``````````````````````2````````54
y``````````````````````````````````12.6g
y=13.07g
答：需向右盘加入13.07克铁.
自己用化学方程式算吧
设：相同质量的稀硫酸质量为X，需向右盘加入铁Z，生成H2 y
Ze + H2So4=ZeSo4 + H2↑
65 2
13 y
y=26/56
M2=13－0.46＝26/56
Fe + H2So4=FeSo4 + H2↑
56 2
Z P
Z-P=26/56①
2Z＝56P②
①带入②
2Z=Z-56
Z=56
答：需向右盘加入56克铁