Concept explainers
Nitromethane,
The standard enthalpy of formation of liquid nitromethaneat 25°C is
- Calculate the enthalpy change in the burning of 1 molliquid nitromethane to form gaseous products at25°C. State explicitly whether the reaction is endothermicor exothermic.
- Would more or less heat be evolved if gaseous nitromethanewere burned under the same conditions?Indicate what additional information (if any) you would need to calculate the exact amount of heat, and show just how you would use this information.
Trending nowThis is a popular solution!
Chapter 12 Solutions
Principles of Modern Chemistry
- Gasohol, a mixture of gasoline and ethanol, C2H5OH, is used as automobile fuel. The alcohol releases energy in a combustion reaction with O2. C2H5OH(l)+3O2(g)2CO2(g)+3H2O(l) If 0.115 g ethanol evolves 3.62 kJ when burned at constant pressure, calculate the combustion enthalpy for ethanol.arrow_forwardThe enthalpy of combustion of diamond is -395.4 kJ/mol. C s, dia O2 g CO2 g Determine the fH of C s, dia.arrow_forwardAnother reaction that is used to propel rockets is N2O4(l)+2N2H4(l)3N2(g)+4H2O(g) This reaction has the advantage that neither product is toxic, so no dangerous pollution is released. When the reaction consumes 10.0 g liquid N2O4, it releases 124 kJ of heat. (a) Is the sign of the enthalpy change positive or negative? (b) What is the value of H for the chemical equation if it is understood to be written in molar quantities?arrow_forward
- Calculate the standard enthalpy of combustion for benzene, C6H6. C6H6() + 15/2 O2(g) 6 CO2(g) + 3 H2O() rH = ? The enthalpy of formation of benzene is known [rH[C6H6()] = +49.0 kJ/mol], and other values needed can be found in Appendix L.arrow_forwardWhen solid iron burns in oxygen gas (at constant pressure) to produce Fe2O3(s), 1651 kJ of heat is released for every 4 mol of iron burned. How much heat is released when 10.3 g Fe2O3(s) is produced (at constant pressure)? What additional information would you need to calculate the heat released to produce this much Fe2O3(s) if you burned iron in ozone gas, O3(g), instead of O2(g)?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_forward
- A 50-mL solution of a dilute AgNO3 solution is added to 100 mL of a base solution in a coffee-cup calorimeter. As Ag2O(s) precipitates, the temperature of the solution increases from 23.78 C to 25.19 C. Assuming that the mixture has the same specific heat as water and a mass of 150 g, calculate the heat q. Is the precipitation reaction exothermic or endothermic?arrow_forwardOne 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_forwardEthylene glycol, HOCH2CH2OH, is used as antifreeze. It is produced from ethylene oxide, C2H4O, by the reaction C2H4O(g)+H2O(l)HOCH2CH2OH(l) Use Hesss law to obtain the enthalpy change for this reaction from the following enthalpy changes: 2C2H4O(g)+5O2(g)4CO2(g)+4H2O(l);H=2612.2kJHOCH2CH2OH(l)+52O2(g)2CO2(g)+3H2O(l);H=1189.8kJarrow_forward
- Chemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage LearningChemistry: Principles and PracticeChemistryISBN:9780534420123Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward MercerPublisher:Cengage LearningGeneral 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 Learning
- ChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage LearningChemistry: An Atoms First ApproachChemistryISBN:9781305079243Author:Steven S. Zumdahl, Susan A. ZumdahlPublisher:Cengage Learning