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?

Polychlorinated biphenyls (PCBs) have been used extensively as dielectric materials in electrical transformers. Because PCBs have been shown to be potentially harmful, analysis for their presence in the environment has become very important. PCBs are manufactured according to the following generic reaction: C12H10+nCl2C12H10nCln.+nHCl This reaction results in a mixture of PCB products. The mixture is analyzed by decomposing the PCBs and then precipitating the resulting Cl asAgCl. a. Develop a general equation that relates the average value of n to the mass of a given mixture of PCBs and the mass of AgCl produced. b. A 0.1947-g sample of a commercial PCB yielded 0.4791 g of AgCl. What is the average value of n for this sample?

What mass of solid NaOH (97.0% NaOH by mass) is required to prepare 1.00 L of a 10.0% solution of NaOH by mass? The density of the 10.0% solution is 1.109 g/mL.

Experiments show that propionic acid (CH3CH2COOH) is a weak acid. Write the chemical equation.

According to the Resource Conservation and Recovery Act (RCRA), waste material is classified as toxic and must be handled as hazardous if the lead concentration exceeds 5 mg/L. By adding chloride ion, the lead ion will precipitate as PbCl2, which can be separated from the liquid portion. Once the lead has been removed, the rest of the waste can be sent to a conventional waste treatment facility. How many grams of sodium chloride must be added to 500 L of a waste solution to reduce the concentration of the Pb2+ ion from 10 to 5 mg/L?

list at least three quantities that must be conserved in chemical reactions.

4.25 When octane is combusted with inadequate oxygen, carbon monoxide may form. If 100 g of octane is burned in 200 g of O2, are conditions conductive to forming carbon monoxide?

One method for determining the purity of aspirin (C9H8O4) is to hydrolyze it with NaOH solution and then to titrate the remaining NaOH. The reaction of aspirin with NaOH is as follows: A sample of aspirin with a mass of 1.427 g was boiled in 50.00 mL of 0.500 M NaOH. After the solution was cooled, it took 31.92 mL of 0.289 M HCl to titrate the excess NaOH. Calculate the purity of the aspirin. What indicator should be used for this titration? Why?

Nickel(II) sulfide, NiS, occurs naturally as the relatively rare mineral millerite. One of its occurrences is in meteorites. To analyze a mineral sample for the quantity of NiS, the sample is dissolved in nitric add to form a solution of Ni(NO3)2. NiS(s) + 4 HNO3(aq) Ni(NO3)2(aq) + 2 NO2(g) + 2 H2O(l) + S(s) The aqueous solution of Ni(NO3)2 is then reacted with the organic compound dimethylglyoxime (C4H8N2O2) to give the red solid Ni((C4H7N2O2)2. Ni(NO3)2(aq) + 2 (C4H8N2O2)(aq) Ni(C4H7N2O2)2 + 2 HNO3(aq) Suppose a 0.468-g sample containing millerite produces 0.206 g of red, solid Ni(C4H7N2O2)2 What is the mass percent of NiS in the sample?