If 36.0 g of mgso4⋅7h2o is thoroughly heated, what mass of anhydrous magnesium sulfate will remain?

Answer is:  mass of anhydrous magnesium sulfate 17,50 grams will remain.
m(MgSO₄·7H₂O) = 36,0 g.
m(MgSO₄) = ?
Make proportion: m(MgSO₄) : m(MgSO₄·7H₂O) = M(MgSO₄) : M(MgSO₄·7H₂O).
m(MgSO₄) : 36,0 g = 120,36 g/mol : 247,47 g/mol.
m(MgSO₄) = 17,50 g.

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