x xмоль
CuSO4+Fe=FeSO4+Cu
1 1
20,8-m(Fe)+m(Cu)=20
20,8-(56x+64x)=20
8x=0,8
x=0,1;
m(Fe)=0,1*56=5,6; m(Cu)=0,1*64=6,4.
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