3. A 1.4639 grams sample of limestone was analyzed for Fe, Ca, and Mg. The iron was determined as Fe2O3 yielding 0.0357 g. Ca was isolated as CaSO4 (MW-136.142) yielding a precipitate of 1.4058g, and Mg was isolated as 0.0672g of Mg2P207 (MW-222.553). Report the amount of Fe, Ca, and Mg in the limestone sample as % by mass Fe2O3, % by mass CaO (MW-56.077) and % by /mass MgO (MW-40.304)| 4 A 516 mg sample containing a mixture of K2SO4 and (NH4)2SO4 was dissolved in water and treated with BaCl2 precipitating the SO42 as BaSO4. The resulting precipitate was isolated by filtration, rinsed free of impurities, and dried to a constant wt, yielding 863.5 mg of BaSO4 (MW-233.391). What is the % by mass K2SO4 (MW-174.260) and (NH4)2SO4 (MW-132.141) in the sample?