Answer:
MgSO_3
Explanation:
As is standard for these sorts of questions, we
assume 100 g of substance, and use the percentage elemental
compositions to calculate an empirical formula.
"Magnesium" = (23.3*g)/(24.31*g*mol^-1) = 0.958*mol
"Sulfur" = (30.7*g)/(32.06*g*mol^-1) = 0.958*mol
"Oxygen" = (46.0*g)/(15.999*g*mol^-1) = 2.86*mol
We divide thru by the smallest molar quantity (0.958*mol) to get and empirical formula of MgSO_3, magnesium sulfite.
Ordinarily you would not be given the percentage of oxygen by mass.
You would be given the percentages of the metal and sulfur, and would
have to assume that the balance was oxygen.
Hope this helps!
-Much love, Makayla
