Fifty food supplement tablets with a total mass of 66.393 g were crushed into powder to analyse the content of FeSO4·7H2O. 2.988 g of the powder were dissolved in HNO3 and heated to convert all the iron to Fe3+. Addition of aqueous NH3 caused quantitative precipitation of Fe2O3·xH2O, which was ignited to give 0.0640 g of Fe2O3. Determine the average weight of FeSO4·7H2O in each tablet.

In one gravimetric analysis, the iron (Fe) in a 1.6374 g of impure iron compound was dissolved with nitric acid, HNO3 to oxidize iron. The precipitate will be formed as hydrous compound. The precipitate was then filtered, rinsed and ignited at 900°C to give anhydrous Fe2O3 weighed of 0.8994 g. Calculate the percentage by mass of Fe in a sample.

Consider the series of reactions to synthesize the alum (KAl(SO4 )2 · xH2O(s)) from the introduction. (a) Assuming an excess of the other reagents, from one mole of aluminum Al (s), how many moles of alum will be produced?  (b) Assuming an excess of the other reagents, from one mole of potassium hydroxide KOH, how many moles of alum will be produced? (c) Assuming an excess of the other reagents, from one mole of sulfuric acid H2SO4 , how many moles of alum will be produced? (d) If you start the synthesis with 1.00 g of Al, 40.0 mL of 1.50 M KOH, and 20.0 mL of 9.00 M H2SO4 , which of the three will be the limiting reagent? (e) Assuming that the product is anhydrous (that there are no waters of hydration), calculate the theoretical yield of alum, in grams, based on the amounts of reagents in part (d). 3. Consider the nickel salt: (NH4 )2Ni(SO4 )2 ·y H2O (Ammonium Nickel Sulfate Hydrate), where y is the number of coordinated waters. (a) Assuming that the product is anhydrous (y = 0),…

1. A sample containing magnetite, Fe;O4, was analyzed by dissolving a 1.5419-g sample in concentrated HCI, giving a mixture of Fe2+ and Fe³+. After adding HNO3 to oxidize any Fe2+ to Fet, the resulting solution was diluted with water and the Fe+ precipitated as Fe(OH)3 by adding NH3. After filtering and rinsing, the residue was ignited, resulting to 0.8525 g of pure Fe2O3. Calculate the: a) % (w/w) Fe b) % (w/w) Fe;O4 in the sample.

When 15.11 ml of 0.102 M K2SO4 solution reacts with 35.00 ml of 0.114 M Pb(C2H3O2)2, predict the theoretical yield of the solid product.

Balance the following equations:

A 6.881-g sample containing magnesium chloride and sodium chloride was dissolved in sufficient water to give 500 mL of solution. Analysis for the chloride content of a 50.0-mL aliquot resulted in the formation of 0.5923 g of AgCl. The magnesium in a second 50.0-mL aliquot was precipitated as MgNH4PO4; on ignition, 0.1796 g of Mg2P2O7 was found. Calculate the percentage of MgCl2 # 6H2O and of NaCl in the sample.

Given: You weigh out exactly 0.200 g of Fe(NH4)2(SO4)2·6H2O and dissolve it in the 100.00 mL volumetric flask. You then pipette 2.00 mL of this solution into the 50.00 mL volumetric flask to prepare the stock standard tris-bipyridyl-iron(II) solution. a. Calculate the molar concentration of iron(II) in this solution in the 50.00 mL volumetric flask. (The MW of Fe(NH4)2(SO4)2·6H2O is 392.14 g/mol) (answer a given the information above)

A 1.1324 g sample of magnetite ore was dissolved in concentrated HCl to give a solution that contained a mixture of Fe2+ and Fe3+. Nitric acid was added and the solution was boiled for a few minutes, which converted all of the iron to Fe3+. The Fe3+ was then precipitated as Fe2O3*xH2O by addition of NH3. After filtration and washing, the residue was ignited at a high temp to give 0.5394 g of pure Fe2O3. What is the percent Fe and the percent Fe3O4 in the sample?

A 1.00 g sample of limonite iron ore, 2Fe203 · 3H20, is dissolved, reduced to Fe2+ and titrated with 20.00 mL of 0.20 M cerium (IV). Calculate the percentage of 2FE203 · 3H20, (FM: 373.38 g/mol) in the sample. Titration reaction: Fe2+ + Ce*+ → Fe3+ + Ce3+