Polychlorinated biphenyls (PCBs) have been used extensivelyas dielectric materials in electrical transformers.Because PCBs have been shown to be potentially harmful,analysis for their presence in the environment hasbecome very important. PCBs are manufactured accordingto the following generic reaction:
This reaction results in a mixture of PCB products. Themixture is analyzed by decomposing the PCBs and thenprecipitating the resulting
a. Develop a general equation that relates the averagevalue of n to the mass of a given mixture of PCBsand the mass of AgCl produced.
b. A 0.1947-g sample of a commercial PCB yielded0.4971 g of AgCl. What is the average value of nfor this sample?
Want to see the full answer?
Check out a sample textbook solutionChapter 4 Solutions
Chemical Principles
- A student set up an experiment for six different trials of the reaction between 1.00-M aqueous acetic acid, CH3COOH, and solid sodium hydrogen carbonate, NaHCO3. CH3COOH(aq) + NaHCO3(s) NaCH3CO2(aq) + CO2(g) + H2O() The volume of acetic acid was kept constant, but the mass of sodium bicarbonate increased with each trial. The results of the tests are shown in the figure. (a) In which trial(s) is the acetic acid the limiting reactant? (b) In which trial(s) is sodium bicarbonate the limiting reactant? (c) Explain your reasoning in parts (a) and (b).arrow_forwardFor each of the changes listed will the rate of the following chemical reaction increase, decrease, or remain the same? Cu(s)+H2SO4(aq)CuSO4(aq)+H2(g) a. the concentration of H2SO4 is increased b. the copper is ground into a powder c. the mixture is stirred rapidly d. the temperature of the solution is increasedarrow_forwardClassify each of the reactions according to one of the four reaction types summarized in Table 18.1. (a) C6H12O6(s) + 6 O2(g) 6 CO2(g) + 6 H2O() rH = 673 kj/mol-rxn rS = 60.4 j/K mol-rxn (b) MgO(s) + C(graphite) Mg(s) + CO(g) rH = 490.7 kJ/mol-rxn rS = 197.9 J/K mol-rxn TABLE 18.1 Predicting Whether a Reaction Will Be Spontaneous Under Standard Conditionsarrow_forward
- Indicate to which of the following types of reactions each of the statements listed applies: combination, decomposition, displacement, exchange, and combustion. More than one answer is possible for a given statement. a. An element may be a reactant. b. An element may be a product. c. A compound may be a reactant. d. A compound may be a product.arrow_forwardClassify each of the reactions according to one of the four reaction types summarized in Table 18.1. (a) Fe2O3(s) + 2 Al(s) 2 Fe(s) + Al2O3(s) rH = 851.5 kj/mol-rxn rS = 375.2 J/K mol-rxn (b) N2(g) + 2 O2(g) 2 NO2(g) rH = 66.2 kJ/mol-rxn rS = 121.6 J/K mol-rxn TABLE 18.1 Predicting Whether a Reaction Will Be Spontaneous Under Standard Conditionsarrow_forward4.65 Using the web, find out how lead “poisons” the catalyst in a catalytic converter.arrow_forward
- Carbon dioxide from the atmosphere weathers, or dissolves, limestone (CaCO3) by the reaction CaCO3(s)+CO2(g)+H2O(l)Ca2(aq)+2HCO3(aq) Obtain H for this reaction. See Table 6.2 for the data.arrow_forwardNickel(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?arrow_forwardEthanol, 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.arrow_forward
- What is the general chemical equation for each of the following types of chemical reactions? a. Exchange reaction b. Decomposition reactionarrow_forwardlist at least three quantities that must be conserved in chemical reactions.arrow_forwardThe carbon dioxide exhaled in the breath of astronauts is often removed from the spacecraft by reaction with lithium hydroxide 2LiOH(s)+CO2(g)Li2CO3(s)+H2O(l) Estimate the grams of lithium hydroxide required per astronaut per day. Assume that each astronaut requires 2.50 103 kcal of energy per day. Further assume that this energy can be equated to the heat of combustion of a quantity of glucose, C6H12O6, to CO2(g) and H2O(l). From the amount of glucose required to give 2.50 103 kcal of heat, calculate the amount of CO2 produced and hence the amount of LiOH required. The H for glucose(s) is 1273 kJ/mol.arrow_forward
- Chemistry: An Atoms First ApproachChemistryISBN:9781305079243Author:Steven S. Zumdahl, Susan A. ZumdahlPublisher:Cengage LearningChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage LearningGeneral, Organic, and Biological ChemistryChemistryISBN:9781285853918Author:H. Stephen StokerPublisher:Cengage Learning
- Chemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage LearningChemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781133949640Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning