Concept explainers
Hydrazine, a component of rocket fuel, undergoes combustion to yield N2 and H2O:
(a) Draw an electron-dot structure for hydrazine, predict the geometry about each nitrogen atom, and tell the hybridization of each nitrogen.
(b) Use the following information to set up a Hess's law cycle, and then calculate
(c) How much heat is released on combustion of 100.0 g ofhydrazine?
Want to see the full answer?
Check out a sample textbook solutionChapter 9 Solutions
LCPO CHEMISTRY W/MODIFIED MASTERING
- The molecular structure shown is of one form of glucose, C6H12O6 Glucose can be oxidized to carbon dioxide and water according to the equation C6H12O6(S) + 6 O2(g)6 CO2(g) + 6 H2O(g) (a) Using the method described in Section 6-6a for estimating enthalpy changes from bond energies, estimate rH for the oxidation of this form of glucose. Make a list of all bonds broken and all bonds formed in this process. (b) Compare your result with the experimental value of 2816 kJ/mol for combustion of glucose. Why might there be a difference between this value and the one you calculated in part (a)?arrow_forwardGiven the following data: NO2(g) NO(g) + O(g)H = 233 kJ 2O3(g) 3O2(g)H = 427 kJ NO(g) + O3(g) NO2(g) + O2(g)H = 199 kJ Calculate the bond energy for the O2 bond, that is, calculate H for: O2(g) 2O(g)H = ?arrow_forwardFructose, C6H1206(S), consists of 5 C-C single bonds, 7 C-O bonds, 7 C-H bonds, and 5 O-H bonds with average bond energies of 348 kJ/mol, 360 kJ/mol, 412 kJ/mol, and 463 kJ/mol respectively. The bond energy for C=O is 799 kJ/mol and O=O is 498 kJ/mol. The molar mass of fructose is 180.12 g/mol. Estimate the change in enthalpy if 2.56 g of fructose undergoes complete combustion at standard temperature and pressure.arrow_forward
- Rank the elements or compounds in the table below in decreasing order of their boiling points. That is, choose 1 next to the substance with the highest boiling point, choose 2 next to the substance with the next highest boiling point, and so on. substance A B C D chemical symbol, chemical formula or Lewis structure H : Cl H Nb Cl5 - N | H : Cl: C : Cl: -D - H · Η Cl I C-H I H boiling point ✓ (Choose one) | (highest) 2 3 4 (lowest) (Choose one) (Choose one) ✓arrow_forwardUsing the bond energy data from your text (or the internet), determine (show calculations for) the approximate enthalpy change , ∆H, for each of the following reactions: (a) Cl2 (g) + 3F2 (g) ⟶ 2ClF3 (g) (b) H2C=CH2 (g) + H2 (g) ⟶ H3CCH3 (g)arrow_forwarda) The following reaction occurs in an open beaker: C2H5OH (g) ---> C2H4(g) + H2O (g) {Bond Energy (kJ/mol): C-H = 415 ; C-C = 345 ; C-O = 350 ; O-H = 464 ; C=C = 611}i) Calculate the ΔH0rxn for this reaction from the given bond energies. kJ ii) Is this reaction an open, closed or isolated system? iii) Would you feel hot or cold if you were near this reaction when it occurred? This is because (choose from I - V) I. the reaction is exothermic and absorbs energy from the surroundings. II. the reaction is exothemic and releases energy to the surroundings. III. the reaction is endothermic and absorbs thermal energy from the surroundings. IV. the reaction is endothermic and loses heat to the surroundings. V. the reaction produces steam which contains a lot of heat.arrow_forward
- The OH covalent bond has a very high bond energy of about 463 kJ / mol. The electrostatic bond of the hydrogen bond has an energy between 10 and 40 kJ / mol. Although the hydrogen bond is relatively weak compared to the covalent bonds, it is stronger than the Van der Waals interactions and plays among other things a primordial role in the biological systems and on the physicochemical properties of water. (as heard in the 1st audio) Thus the consequences of the existence of strong hydrogen bonds are remarkable on the temperatures of change of state of water compared to compounds of similar structure. According to the following graph, 2- What are these values for water? What is the temperature range of existence of liquid water at normal pressure (1 atm)? What would these values be if the water molecule were not also polar (Extrapolate by following the dotted lines)? 100 °C 60 boiling point H2O 20 -20 H2Se H2S H,Te -60 freezing point -80 40 80 g/moi 160 masse molaire températurearrow_forwardBalance the ethanol combustion reaction shown below and use the bond energies to estimate the enthalpy change for the combustion of 2.07 moles of ethanol. C2H;OH(1) + O2(9) → CO2(9) + H»0(g) Table of bond enthalpies is in the Equation Sheet. ΔΗ kJarrow_forward5. Consider the reaction between hydrazine and hydrogen to produce ammonia, N2H4(g)+H2(g)→2NH3(g)N2H4(g)+H2(g)→2NH3(g). Use enthalpies of formation and bond enthalpies to estimate the enthalpy of the nitrogen-nitrogen bond in N2H4N2H4. (Hint: In an N2H4N2H4 molecule, each NN atom has single bonds to the adjacent NN atom and two HH atoms. In an NH3NH3 molecule, the central NN atom has single bonds to three HH atoms.)arrow_forward
- Rank the elements or compounds in the table below in decreasing order of their boiling points. That is, choose 1 next to the substance with the highest boiling point, choose 2 next to the substance with the next highest boiling point, and so on.arrow_forwardRank the elements or compounds in the table below in decreasing order of their boiling points. That is, choose 1 next to the substance with the highest boiling point, choose 2 next to the substance with the next highest boiling point, and so on. substance B C D chemical symbol, chemical formula or Lewis structure HI H H ** HICIO-C-H со Cao I I H H H II HICICIOIH I | | H H boiling point (Choose one) (Choose one) (Choose one) • (Choose one)arrow_forwardIn a hydrogen molecule, the two hydrogen atoms are held together by a single bond with a bond energy of 436 kJ/mol of hydrogen. In other words, to break the H-H bonds in one mole of molecular hydrogen requires the expenditure of 436 kJ of energy. Using the balanced chemical equation for the formation of water from oxygen and hydrogen (shown above), and interpreting the stoichiometric coefficients as mole amounts, how much energy must be expended in breaking the H-H bonds? kJarrow_forward
- Chemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage LearningChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage Learning
- 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 & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781133949640Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning