Concept explainers
A lead ore, galena, consisting mainly of lead(II) sulfide, is the principal source of lead. To obtain the lead, the ore is first heated in the air to form lead oxide.
The oxide is then reduced to metal with carbon.
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Chapter 8 Solutions
Chemistry: Principles and Reactions
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- A piece of lead of mass 121.6 g was heated by an electrical coil. From the resistance of the coil, the current, and the Time the current flowed, it was calculated that 235 J of heat was added to the lead. The temperature of the lead rose from 20.4C to 35.5C. What is the specific heat of the lead?arrow_forwardUsing the data in Appendix G, calculate the standard enthalpy change for each of the following reactions: (a) Si(s)+2F2(g)SiF4(g) (b) 2C(s)+2H2(g)+O2(g)CH3CO2H(l) (c) CH4(g)+N2(g)HCN(g)+NH3(g) ; (d) CS2(g)+3Cl2(g)CCl4(g)+S2Cl2(g)arrow_forwardA rebreathing gas mask contains potassium superoxide, KO2, which reacts with moisture in the breath to give oxygen. 4KO2(s)+2H2O(l)4KOH(s)+3O2(g) Estimate the grams of potassium superoxide required to supply a persons oxygen needs for one hour. Assume a person requires 1.00 102 kcal of energy for this time period. 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 1.00 102 kcal of heat, calculate the amount of oxygen consumed and hence the amount of KO2 required. The ff0 for glucose(s) is 1273 kJ/mol.arrow_forward
- One step in the manufacturing of sulfuric acid is the conversion of SO2(g) to SO3(g). The thermochemical equation for this process is SO2(g)+12O2(g)SO3(g)H=98.9kJ The second step combines the SO3 with H2O to make H2SO4. (a) Calculate the enthalpy change that accompanies the reaction to make 1.00 kg SO3(g). (b) Is heat absorbed or released in this process?arrow_forwardAn industrial process for manufacturing sulfuric acid, H2SO4, uses hydrogen sulfide, H2S, from the purification of natural gas. In the first step of this process, the hydrogen sulfide is burned to obtain sulfur dioxide, SO2. 2H2S(g)+3O2(g)2H2O(l)+2SO2(g);H=1124kJ The density of sulfur dioxide at 25C and 1.00 atm is 2.62 g/L, and the molar heat capacity is 30.2 J/(mol C). (a) How much heat would be evolved in producing 1.00 L of SO2 at 25C and 1.00 atm? (b) Suppose heat from this reaction is used to heat 1.00 L of the SO2 from 25C to 500C for its use in the next step of the process. What percentage of the heat evolved is required for this?arrow_forwardAs the gas trapped in a cylinder with a movable piston cools, 1.34 kJ of work is done on the gas by the surroundings. If the gas is at a constant pressure of 1.33 105 Pa, what is the change of volume (in L) of the gas?arrow_forward
- When steam condenses to liquid water, 2.26 kJ of heat is released per gram. The heat from 168 g of steam is used to heat a room containing 6.44 104 g of air (20 ft 12 ft 8 ft). The specific heat of air at normal pressure is 1.015 J/(gC). What is the change in air temperature, assuming the heat from the steam is all absorbed by air?arrow_forwardCombustion of table sugar produces CO2(g) and H2O( l). When 1.46 g table sugar is combusted in a constant-volume (bomb) calorimeter, 24.00 kJ of heat is liberated. a. Assuming that table sugar is pure sucrose, C12H22O11 (s), write the balanced equation for the combustion reaction. b. Calculate E in kJ/mol C12H22O11 for the combustion reaction of sucrose.arrow_forward
- General Chemistry - Standalone book (MindTap Cour...ChemistryISBN:9781305580343Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; DarrellPublisher:Cengage LearningChemistry: Principles and PracticeChemistryISBN:9780534420123Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward MercerPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781133949640Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning
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