This problem is providing us with the percent composition of a compound containing magnesium, nitrogen, oxygen and water. Thus, the empirical formula is required and found to be Mg(NO₃)₂·6H₂O.
<h3>Empirical formulas</h3>
In chemistry, empirical formulas are used in order to figure out the minimum whole-number representation of a molecular formula, which contains the actual number of atoms.
Thus, we start determining it by assuming the given percentages as masses and calculating the moles with the atomic or molar mass of the involved species:
Next, we divide by the 0.386 as the smallest number of moles in order to determine their subscripts in the chemical formula:
Hence, the empirical formula turns out to be Mg(NO₃)₂·6H₂O, which is actually a hydrate (hexahydrate).
Learn more about percent composition: brainly.com/question/12247957
Answer: see the photo attached. (:
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