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The propane fuel
If a pork roast must absorb
kJ to fully cook, and if only 10% of the heat produced by the barbecue is absorbed by the roast, what mass
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Introductory Chemistry (6th Edition)
- Nitrogen monoxide, a gas recently found to be involved in a wide range of biological processes, reacts with oxygen to give brown NO2 gas. 2 NO(g) + O2(g) NO2(g)rH = 114.1 kJ/mol-rxn Is this reaction endothermic or exothermic? What is the enthalpy change if 1.25 g of NO is converted completely to NO2?arrow_forward62 Ammonium dinitramide (ADN), NH4N(NO2)2, was considered as a possible replacement for aluminium chloride as the oxidizer in the solid fuel booster rockets used to launch the space shuttle. When detonated by a spark, AND rapidly decomposes to produce a gaseous mixture of N2,O2, and H2O. (This is not a combustion reaction. The ADN is the only reactant.) The reaction releases a lot of heat, so the gases are initially formed at high temperature and pressure. The thrust of the rocket results mainly from the expansion of this gas mixture. Suppose a 2.3-kg sample of ADN is denoted and decomposes completely to give N2,O2, and H2O. If the resulting gas mixture expands until it reaches a temperature of 100°C and a pressure of 1.00 atm, what volume will it occupy? Is your answer consistent with the proposed use of ADN as a rocket fuel?arrow_forward4.61 What is actually measured by the octane ratings of different grades of gasoline?arrow_forward
- Water gas, a mixture of carbon monoxide and hydrogen, is produced by treating carbon (in the form of coke or coal) with steam at high temperatures. (See Study Question 83.) C(s) + H2O(g) CO(g) + H2(g) Not all of the carbon available is converted to water gas since some is burned to provide the heat for the endothermic reaction of carbon and water. What mass of carbon must be burned (to CO2 gas) to provide the energy to convert 1.00 kg of carbon to water gas?arrow_forwardThe equation for the fermentation of glucose to alcohol and carbon dioxide is: C6H12O6(aq) 2C2H5OH(aq) + 2CO2(g) The enthalpy change for the reaction is 67 kJ. Is this reaction exothermic or endothermic? Is energy, in the form of heat, absorbed or evolved as the reaction occurs?arrow_forwardChlorine dioxide, ClO2, is a reddish yellow gas used in bleaching paper pulp. The average speed of a ClO2 molecule at 25C is 306 m/s. What is the kinetic energy (in joules) of a ClO2 molecule moving at this speed?arrow_forward
- A 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_forwardChloromethane, CH3Cl, a compound found throughout the environment, is formed in the reaction of chlorine atoms with methane. CH4(g) + 2 Cl(g) CH3Cl(g) + HCl(g) (a) Calculate the enthalpy change for the reaction of CH4(g) and CI atoms to give CH3CI(g) and HCl(g). Is the reaction exo- or endothermic? (b) Draw an energy level diagram that shows how the various enthalpies in this problem are related.arrow_forwardThe enthalpy change for the reaction of hydrogen gas with fluorine gas (o produce hydrogen fluoride is 542 U for the equation as written: mg src=Images/HTML_99425-10-41QAP_image001.jpg alt="" align="top"/> l type='a'> What is the enthalpy change per mole of hydrogen fluoride produced? Is the reaction exothermic or endothermic as written? What would be the enthalpy change for the reverse of the given equation (that 1%, for the decomposition of HF into its constituent elements)?arrow_forward
- A power plant is driven by the combustion of a complex fossil fuel having the formula C11H7S. Assume the air supply is composed of only N2 and O2 with a molar ratio of 3.76:1.00, and the N2 remains unreacted. In addition to the water produced, the fuels C is completely combusted to CO2 and its sulfur content is converted to SO2. In order to evaluate gases emitted at the exhaust stacks for environmental regulation purposes, the nitrogen supplied with the air must also be included in the balanced reactions. a Including the N2 supplied m the air, write a balanced combustion equation for the complex fuel assuming 100% stoichiometric combustion (i.e., when there is no excess oxygen in the products and the only C-containing product is CO2). Except in the case of N2, use only integer coefficients. b Including N2 supplied in the air, write a balanced combustion equation for the complex fuel assuming 120% stoichiometric combustion (i.e., when excess oxygen is present in the products and the only C-containing product is CO2). Except in the case of use only integer coefficients c Calculate the minimum mass (in kg) of air required to completely combust 1700 kg of C11H7S. d Calculate the air/fuel mass ratio, assuming 100% stoichiometric combustion. e Calculate the air/fuel mass ratio, assuming 120% stoichiometric combustion.arrow_forwardWithout doing calculations, decide whether each of the following is exo- or endothermic. (a) the combustion of natural gas (b) the decomposition of glucose, C6H12O6, to carbon and waterarrow_forward
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