A mixture of `FeO` and `Fe_(3)O_(4)` when heated in air to a constant weight, gains `5%` of its weight. Find the composition of the initial mixture.

Explanation

`2FeO+(1)/(2)O_2toFe_2O_3`
`2Fe_3O_4+(1)/(2)O_2to3Fe_2O_3`
Let the weights of FeO and `Fe_3O_4` be x and y g, respectively. `x+y=100` …(i)
Now, `2xx72 g Feo` gives `Fe_2O_3=160g`
x g FeO gives `Fe_2O_3=160g`
`x h FeO gives Fe_2O_3=(160xx x)/(144)g`
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