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93 The complete combustion of octane can be used as a model for the burning of gasoline:
Assuming that this equation provides a reasonable model of the actual combustion process, what volume of air at 1.0 atm and 25°C must be taken into an engine to burn 1 gallon of gasoline? (The partial pressure of oxygen in air is 0.21 atm and the density of liquid octane is 0.70 g/mL.)
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Chemistry for Engineering Students
- Nitrogen trifluoride is prepared by the reaction of ammonia and fluorine. 4 NH3(g) + 3 F2(g) 3 NH4F(s) + NF3(g) If you mix NH3 with F2 in the correct stoichiometric ratio, and if the total pressure of the mixture is 120 mm Hg, what are the partial pressures of NH3 and F2? When the reactants have been completely consumed, what is the total pressure in the flask? (Assume T is constant.)arrow_forwardA sample of a smoke stack emission was collected into a 1.25-L tank at 752 mm Hg and analyzed. The analysis showed 92% CO2, 3.6% NO, 1.2% SO2, and 4.1% H2O by mass. What is the partial pressure exerted by each gas?arrow_forward97 Homes in rural areas where natural gas service is not available often rely on propane to fuel kitchen ranges. The propane is stored as a liquid, and the gas to be burned is produced as the liquid evaporates. Suppose an architect has hired you to consult on the choice of a propane tank for such a new home. The propane gas consumed in 1.0 hour by a typical range burner at high power would occupy roughly 165 L at 25°C and 1.0 atm, and the range chosen by the client will have six burners. If the tank under consideration holds 500.0 gallons of liquid propane, what is the minimum number of hours it would take for the range to consume an entire tankful of propane? The density of liquid propane is 0.5077 kg/L.arrow_forward
- Hydrogen azide, HN3, decomposes on heating by the following unbalanced equation: HN3O(g)N2(g)+H2(g) If 3.0 atm of pure HN3(g) is decomposed initially, what is the final total pressure in the reaction container? What are the partial pressures of nitrogen and hydrogen gas? Assume the volume and temperature of the reaction container are constant.arrow_forwardCarbon monoxide, CO, and oxygen, O2, react according to 2CO(g)+O2(g)2CO2(g) Assuming that the reaction takes place and goes to completion, determine what substances remain and what their partial pressures are after the valve is opened in the apparatus represented in the accompanying figure. Also assume that the temperature is fixed at 300 K.arrow_forwardUrea (H2NCONH2) is used extensively as a nitrogen source in fertilizers. It is produced commercially from the reaction of ammonia and carbon dioxide: 2NH3(g)+CO2(g)PressureHeatH2NCONH2(s)+H2O(g) Ammonia gas at 223C and 90. atm flows into a reactor at a rate of 500. L/min. Carbon dioxide at 223C and 45 atm flows into the reactor at a rate of 600. L/min. What mass of urea is produced per minute by this reaction assuming 100% yield?arrow_forward
- 105 The decomposition of mercury(II) thiocyanate produces an odd brown snake-like mass that is so unusual the process was once used in fireworks displays. There are actually several reactions that take place when the solid Hg(SCN)2 is ignited: 2Hg(SCN)2(s)2HgS(s)+CS2(s)+C3N4(s)CS2(s)+3O2(g)CO2(g)+2SO2(g)2C3N4(s)3(CN)2(g)+N2(g)HgS(s)+O2(g)Hg(l)+SO2(g) A 42.4-g sample of Hg(SCN)2 is placed into a 2.4-L vessel at 21°C. The vessel also contains air at a pressure of 758 torr. The container is sealed and the mixture is ignited, causing the reaction sequence above to occur. Once the reaction is complete, the container is cooled back to the original temperature of 21°C. (a) Without doing numerical calculations, predict whether the final pressure in the vessel will be greater than, less than, or equal to the initial pressure. Explain your answer. (b) Calculate the final pressure and compare your result with your prediction. (Assume that the mole fraction of O2 in air is 0.21.)arrow_forwardIn a typical automobile engine, a gasoline vapor-air mixture is compressed and ignited in the cylinders of the engine. This results in a combustion reaction that produces mainly carbon dioxide and water vapor. For simplicity, assume that the fuel is C8H18 and has a density of 0.760 g/mL. (a) Calculate the partial pressures of N2 and 02 in the air before it goes into the cylinder; assume the atmospheric pressure is 734 mmHg. (b) Consider the case where the air, without any fuel added, is compressed in the cylinder to seven times atmospheric pressure, the compression ratio of many modem automobile engines. Calculate the partial pressures of N2 and O2 at this pressure. (c) Now consider the case where 0.050 mL gasoline is added to the air in the cylinder just before compression and completely vaporized. Assume that the volume of the cylinder is 485 mL and the temperature is 150C. Calculate the partial pressure of the gasoline vapor. (d) Calculate the amount (mol) of oxygen required to bum the gasoline in part (c) completely to CO2 and H2O. (e) The combustion reaction in the cylinder creates temperatures in excess of 1200K. Due to the high temperature, some of the nitrogen and oxygen in the air reacts to form nitrogen monoxide. If 10% of the nitrogen is converted to NO, calculate the mass (g) of NO produced by this combustion. (f) Hot-rod cars use another oxide of nitrogen, dinitrogen monoxide, to create an extra burst in power. When such a power boost is needed, dinitrogen monoxide gas is injected into the cylinders where it reacts with oxygen to form NO. Calculate the mass of dinitrogen monoxide that would have to be injected to form the same quantity of NO as produced in part (e). Assume that sufficient oxygen is present to do so.arrow_forwardYou have a 550.-mL tank of gas with a pressure of 1.56 atm at 24 C. You thought the gas was pure carbon monoxide gas, CO, but you later found it was contaminated by small quantities of gaseous CO2 and O2. Analysis shows that the tank pressure is 1.34 atm (at 24 C) if the CO2 is removed. Another experiment shows that 0.0870 g of O2 can be removed chemically. What are the masses of CO and CO2 in the tank, and what is the partial pressure of each of the three gases at 25 C?arrow_forward
- A 1.0-L flask contains 10.0 g each of O2 and CO2 at 25 C. (a) Which gas has the greater partial pressure, O2 or CO2, or are they the same? (b) Which molecules have the greater rms speed, or are they the same? (c) Which molecules have the greater average kinetic energy, or are they the same?arrow_forwardA mixture contained calcium carbonate, CaCO3, and magnesium carbonate, MgCO3. A sample of this mixture weighing 7.85 g was reacted with excess hydrochloric acid. The reactions are CaCO3(g)+2HCL(aq)CaCl2(aq)+H2O(I)+CO2(g)MgCO3(s)+2HCL(aq)MgCl2(aq)+H2O(I)+CO2(g) If the sample reacted completely and produced 1.94 L of carbon dioxide, CO2, at 25C and 785 mmHg, what were the percentages of CaCO3 and MgCO3 in the mixture?arrow_forwardAmmonia gas is synthesized by combining hydrogen and nitrogen: 3 H2(g) + N2(g) 2 NH3(g) (a) If you want to produce 562 g of NH3, what volume of H2 gas, at 56 C and 745 mm Hg, is required? (b) Nitrogen for this reaction will be obtained from air. What volume of air, measured at 29 C and 745 mm Hg pressure, will be required to provide the nitrogen needed to produce 562 g of NH3? Assume the sample of air contains 78.1 mole % N2.arrow_forward
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