Why the empirical formula of copper oxide cannot be determine by using the same technique as magnesium oxide?
The empirical formula of a compound is determined by analyzing the ratios of elements present. Since both copper and magnesium can form oxides with different oxidation states, the technique cannot be the same because the ratios of elements in their oxides will be different. Copper can form both Cu2O and CuO, while magnesium only forms MgO.