`A` mixture of `CuSO_(4).5H_(2)O` and `MgSO_(4).7H_(2)O` was heated until all the water was driven off If `5.0g` if mixture gave `3g` of anhydrous salts, what was the percentage by mass of `CuSO_(4).5H_(2)O` in the original mixture :

Answer

`74.4`

Explanation

Let the mixture contain `x g CuSO_(4). 5H_(2)O`.
`implies (x)/(249)xx159+(5-x)/(246)xx120=3impliesx=3.72`
implies Mass percentage of `CuSO_(4).5H_(2)O = 74.4`