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A 1.5380g sample of iron ore is dissolved in a
问题详情
A 1.5380g sample of iron ore is dissolved in acid，the iron is reduced to the +2 oxidation state quantitatively and titrated with 43.50mL of KMnO4 solution(Fe2+→Fe3+),1.000 mL of which is equivalent to 11.17 mg of iron． Express the results of the analysis as (1)w(Fe)；(2)w(Fe2O3)；(3)w(Fe3O4)．
参考答案
Solution：
The reaction is
(1)1.000 mL of which is equivalent to 11.17 mg of iron，therefore，
C(Fe)mol=0.3159$n(Fe2O3)=(1/2)n(Fe2+)
C(Fe3O4)=0.4517$n(Fe3O4)=(1/3)n(Fe2+)
thequantityofFeelement=43.5*11.7mgFe%=43.5*11.7mg/1.5380gFe2O3%=[43.5*11.7mg/(112/156)]/1.5380g
=0.4365
