Chapter 12, Problem 29P

A 1.345-g sample of a compound of barium and oxygen was dissolved in hydrochloric acid to give a solution of barium ion, which was then precipitated with an excess of potassium chromate to give 2.012 g of barium chromate, BaCrO4. What is the formula of the compound?

1. Sometimes a reaction can fall in more than one category. Into what category (or categories) does the reaction of Ba(OH)2(aq) + H+PO4(aq) fit? acid-base and oxidation-reduction oxidation-reduction acid-base and precipitation precipitation

Potassium permanganate (KMnO4) solutions are used for the determination of Fe2+ in samples of unknown concentration. As a laboratory assistant, you are supposed to prepare 500 mL of a 0.1000 M KMnO4 solution. What mass of KMnO4, in grams, do you need?

Nitric acid is produced commercially by the Ostwald process, represented by the following equations: 4NH3(g)+5O24NO(g)+6H2O(g)2NO(g)+O2(g)2NO2(g)3NO2(g)+H2O(l)2HNO3(aq)+NO(g) What mass of NH3 must be used to produce 1.0 106 kg HNO3 by the Ostwald process? Assume 100% yield in each reaction, and assume that the NO produced in the third step is not recycled.

Magnesium metal (a component of alloys used in aircraft and a reducing agent used in the production of uranium, titanium, and other active metals) is isolated from sea water by the following sequence of reactions: Mg2+(aq)+Ca(OH)2(aq)Mg(OH)2(s)+Ca2+(aq)Mg(OH)2(s)+2HCl(aq)MgCl2(s)+2H2O(l)MgCl2(l)electrolysisMg(s)+Cl2+Cl2(g) Sea water has a density of 1.026 g/cm3 and contains 1272 parts per million of magnesium a5 Mg2+(aq) by mass. What mass, in kilograms, of Ca(OH)2; is required to precipitate 99.9% of the magnesium in 1.00103 L of sea water?

Phosphoric acid is prepared by dissolving phosphorus(V) oxide, P4O10, in water. What is the balanced equation for this reaction? How many grams of P4O10 are required to make 1.19 L of aqueous solution containing 5.50% phosphoric acid by mass? The density of the solution is 1.025 g/mL.

Ethanol, C2H5OH, is a gasoline additive that can be produced by fermentation of glucose. C6H12O62C2H5OH+2CO2 (a) Calculate the mass (g) of ethanol produced by the fermentation of 1.000 lb glucose. (b) Gasohol is a mixture of 10.00 mL ethanol per 90.00 mL gasoline. Calculate the mass (in g) of glucose required to produce the ethanol in 1.00 gal gasohol. Density of ethanol = 0.785 g/mL. (c) By 2022, the U. S. Energy Independence and Security Act calls for annual production of 3.6 1010 gal of ethanol, no more than 40% of it produced by fermentation of corn. Fermentation of 1 ton (2.2 103 lb) of corn yields approximately 106 gal of ethanol. The average corn yield in the United States is about 2.1 105 lb per 1.0 105 m2. Calculate the acreage (in m2) required to raise corn solely for ethanol production in 2022 in the United States.

You are given a solid mixture of NaNO2 and NaCl and are asked to analyze it for the amount of NaNO2 present. To do so, you allow the mixture to react with sulfamic acid, HSO3NH2, in water according to the equation NaNO2(aq) + HSO3NH2(aq) NaHSO4(aq) + H2O() + N2(g) What is the weight percentage of NaNO2 in 1.232 g of the solid mixture if reaction with sulfa-mic acid produces 295 mL of dry N2 gas with a pressure of 713 mm Hg at 21.0 C?

Iron oxide ores, commonly a mixture of FeO and Fe2O3, are given the general formula Fe3O4. They yield elemental iron when heated to a very high temperature with either carbon monoxide or elemental hydrogen. Balance the following equations for these processes: Fe3O4(s)+H2(g)Fe(s)+H2O(g)Fe3O4(s)+CO(g)Fe(s)+CO2(g)