Đáp án: `m_{KMnO_4}=31,6g`
Giải:
`n_{Cl_2}=\frac{11,2}{22,4}=0,5` `(mol)`
Phương trình phản ứng:
`2KMnO_4+16HCl -> 2MnCl_2+2KCl+5Cl_2+8H_2O`
Ta có:
`n_{KMnO_4}=\frac{2n_{Cl_2}}{5}=\frac{2.0,5}{5}=0,2` `(mol)`
Lượng `KMnO_4` cần dùng là:
`m_{KMnO_4}=0,2.158=31,6` `(g)`
`2KMnO_4+16HCl->2MnCl_2+2KCl+5Cl_2+8H_2O`
`n_(Cl_2)=(11,2)/(22,4)=0,5(mol)`
`n_(KMnO_4)=2/5n_(Cl_2)=2/5 .0,5=0,2(mol)`
`m_(KMnO_4)=0,2.(39+55+16.4)=31,6(g)`
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