Answer:
2,341g of CuSO₄.5H₂O
Explanation:
It is possible to assume all loses water comes from CuSO₄.5H₂O. Thus:
0,8445g H₂O (1mol H₂O / 18,015g) = 0,04688 moles of water.
As 1 mole of contains 5 moles of water, moles of CuSO₄.5H₂O are:
0,04688 moles H₂O × (1 mole CuSO₄.5H₂O / 5 moles H₂O) = 9,38x10⁻³ moles of CuSO₄.5H₂O
The molecular mass of CuSO₄.5H₂O is 249,69g/mol. Thus, mass of 9,38x10⁻³ moles of CuSO₄.5H₂O is:
9,38x10⁻³ moles of CuSO₄.5H₂O × (249,69g / mol) =
2,341g of CuSO₄.5H₂O is the maximum quantity of CuSO₄.5H₂O that could be in the sample.
I hope it helps!