11:36Bond Energy & Bond Length, Forces of Attraction & Repulsion - ChemistryThe Organic Chemistry Tutor404views
Multiple ChoiceConsider the following equation:Determine the bond enthalpy value for the F–S bond.1232views4comments
Multiple ChoiceUse the bond energies to estimate the enthalpy of reaction for the combustion of 5 moles of acetylene:6361views2rank4comments
Multiple ChoiceCalculate the enthalpy of the following reaction based on average bond enthalpies. 361views
Textbook QuestionThe graph shows how potential energy changes as a function of the distance between two atoms. (LO 7.2) What is the length of the bond between the two atoms? (a) 3.4 angstroms (b) 3.8 angstroms (c) 6.0 angstroms (d) 8.0 angstroms607views
Textbook QuestionThe following plot shows the potential energy of two Cl atoms as a function of the distance between them. (c) If the Cl2 molecule is compressed under higher and higher pressure, does the Cl–Cl bond become stronger or weaker? 682views
Textbook QuestionIsomers are molecules that have the same chemical formula but different arrangements of atoms, as shown here for two isomers of pentane, C5H12. (a) Do you expect a significant difference in the enthalpy of combustion of the two isomers? Explain.1509views1rank
Textbook QuestionWhat is the best prediction for the carbon–oxygen bond length in the carbonate anion, CO3 2-? (LO 7.14) Data for average carbon-oxygen bond lengths: (a) 143 pm (b) 132 pm (c) 121 pm (d) 118 pm731views
Textbook Question(b) Based on aver- age bond enthalpies, would you expect a photon capable of dissociating a C ¬ Cl bond to have sufficient energy to dis- sociate a C ¬ Br bond?393views
Textbook QuestionExplain the difference in the bond dissociation energies for the following bonds: (C-F, 450 kJ/mol), (N-F, 270 kJ/mol), (O-F, 180 kJ/mol), (F-F, 159 kJ/mol).1171views
Textbook QuestionState whether each of these statements is true or false. (e) The longer the bond, the more energy is stored chemical bonds.539views1rank
Textbook QuestionHydrogenation reactions are used to add hydrogen across double bonds in hydrocarbons and other organic compounds. Use average bond energies to calculate ΔHrxn for the hydrogenation reaction. H2C'CH2( g) + H2( g)¡H3C¬CH3( g)2652views
Textbook QuestionEthanol is a possible fuel. Use average bond energies to calculate ΔHrxn for the combustion of ethanol. CH3CH2OH( g) + 3 O2( g)¡2 CO2( g) + 3 H2O( g)2892views
Textbook QuestionIn the Chemistry and the Environment box on free radicals in this chapter, we discussed the importance of the hydroxyl radical in reacting with and eliminating many atmospheric pollutants. However, the hydroxyl radical does not clean up everything. For example, chlorofluorocarbons—which destroy stratospheric ozone—are not attacked by the hydroxyl radical. Consider the hypothetical reaction by which the hydroxyl radical might react with a chlorofluorocarbon: OH( g) + CF2Cl2( g)¡HOF( g) + CFCl2( g) Use bond energies to explain why this reaction is improbable. (The C¬F bond energy is 552 kJ>mol.)726views
Textbook QuestionUse bond enthalpies in Table 5.4 to estimate H for each of the following reactions: (a)944views
Textbook QuestionConsider the collection of nonmetallic elements: B, As, O, and I. (b) Which two would form the longest single bond?396views
Textbook QuestionThe P¬P bond length in white phosphorus is 189 pm. The Cl¬Cl bond length in Cl2 is 199 pm. (b) What bond length is predicted for PCl3, using the atomic radii in Figure 7.7?771views
Textbook QuestionThe P¬P bond length in white phosphorus is 189 pm. The Cl¬Cl bond length in Cl2 is 199 pm. (a) Based on these data, what is the predicted P¬Cl bond length in phosphorus trichloride, PCl3, in which each of the three Cl atoms is bonded to the P atom?1100views
Textbook Question(a) The nitrogen atoms in an N2 molecule are held together by a triple bond; use enthalpies of formation in Appendix C to estimate the enthalpy of this bond, D(N‚N). (b) Consider the reaction between hydrazine and hydrogen to produce ammonia, N2H41g2 + H21g2¡2 NH31g2. Use enthalpies of formation and bond enthalpies to estimate the enthalpy of the nitrogen– nitrogen bond in N2H4. (c) Based on your answers to parts (a) and (b), would you predict that the nitrogen–nitrogen bond in hydrazine is weaker than, similar to, or stronger than the bond in N2 ?1614views
Textbook QuestionConsider the reaction 2 H21g2 + O21g2¡2 H2O1l2. (a) Use the bond enthalpies in Table 5.4 to estimate H for this reaction, ignoring the fact that water is in the liquid state.496views
Textbook QuestionTwo compounds are isomers if they have the same chemical formula but different arrangements of atoms. Use Table 8.3 to estimate H for each of the following gas-phase isomerization reactions and indicate which isomer has the lower enthalpy. (d) Methyl isocyanide Acetonitrile1352views
Textbook QuestionIf hydrogen were used as a fuel, it could be burned according to this reaction: H2( g) + 1 2 O2( g)¡H2O( g) Use average bond energies to calculate ΔHrxn for this reaction.672views
Textbook QuestionIf hydrogen were used as a fuel, it could be burned according to this reaction: H2( g) + 1 2 O2( g)¡H2O( g) Use average bond energies to calculate ΔHrxn for the combustion of methane (CH4).752views
Textbook QuestionIf hydrogen were used as a fuel, it could be burned according to this reaction: H2( g) + 1 2 O2( g)¡H2O( g) Which fuel yields more energy per mole?378views
Textbook QuestionIf hydrogen were used as a fuel, it could be burned according to this reaction: H2( g) + 1 2 O2( g)¡H2O( g) Which fuel yields more energy per gram?822views
Textbook QuestionCalculate ΔHrxn for the combustion of octane (C8H18), a component of gasoline, by using average bond energies and then calculate it using enthalpies of formation from Appendix IIB. What is the percent difference between your results? Which result would you expect to be more accurate?2396views
Textbook QuestionThe heat of atomization is the heat required to convert a molecule in the gas phase into its constituent atoms in the gas phase. The heat of atomization is used to calculate average bond energies. Without using any tabulated bond energies, calculate the average C¬Cl bond energy from the following data: the heat of atomization of CH4 is 1660 kJ>mol, and the heat of atomization of CH2Cl2 is 1495 kJ>mol.1981views1rank
Textbook QuestionCalculate the heat of atomization (see previous problem) of C2H3Cl, using the average bond energies in Table 9.3.1393views1rank
Textbook QuestionSulfur tetrafluoride 1SF42 reacts slowly with O2 to form sulfur tetrafluoride monoxide 1OSF42 according to the following unbalanced reaction: SF41g2 + O21g2¡OSF41g2 The O atom and the four F atoms in OSF4 are bonded to a central S atom. (c) Use average bond enthalpies (Table 8.3) to estimate the enthalpy of the reaction. Is it endothermic or exothermic?678views
Textbook Question(a) Compare the bond enthalpies (Table 8.3) of the carbon– carbon single, double, and triple bonds to deduce an average p@bond contribution to the enthalpy. What fraction of a single bond does this quantity represent?1096views
Textbook QuestionCalculate an approximate heat of combustion for ethane (C2H6) in kilojoules by using the bond dissocation energies in Table 9.3. (The strength of the O'O bond is 498 kJ/ mol, and that of a C ' O bond in CO2 is 804 kJ/mol.)1690views
Textbook Question(a) Use average bond enthalpies (Table 8.3) to estimate H for the atomization of naphthalene, C10H8:811views
Textbook QuestionUse the data in Table 9.3 to calculate an approximate ∆H° in kilojoules for the synthesis of hydrazine from ammonia: 2 NH3(g) + Cl2(g) → N2H4(g) + 2 HCl(g)1076views
Textbook QuestionUse average bond enthalpies from Table 8.4 to estimate the enthalpies of the following gas-phase reactions: Reaction 1: HF1g2 + H2O1g2 Δ F-1g2 + H3O+1g2 Reaction 2: HCl1g2 + H2O1g2 Δ Cl-1g2 + H3O+1g2 Are both reactions exothermic? How do these values relate to the different strengths of hydrofluoric and hydrochloric acid?1365views1rank
Textbook Question(b) When subjected to high pressure and heated, polyvinyl chloride converts to diamond. During this transformation which bonds are most likely to break first?306views
Textbook Question(a) In polyvinyl chloride shown in Table 12.6, which bonds have the lowest average bond enthalpy?2229views
Textbook QuestionThe reaction S81g2 S 4 S21g2 has ΔH° = + 237 kJ (b) The average S ¬ S bond dissociation energy is 225 kJ/mol. Using the value of ΔH° given above, what is the S ' S double bond energy in S21g2?566views
Textbook QuestionThe F ¬ F bond in F2 is relatively weak because the lone pairs of electrons on one F atom repel the lone pairs on the other F atom; Kp = 7.83 at 1500 K for the reaction F21g2 ∆ 2 F1g2. (c) Why is the F ¬ F bond in F2 weaker than the Cl ¬ Cl bond in Cl2?1344views
Textbook QuestionPhosgene, COCl21g2, is a toxic gas used as an agent of warfare in World War I. (b) Using the table of bond dissociation energies (Table 9.3) and the value ΔH°f = 716.7 kJ>mol for C(g), estimate ΔH° f for COCl21g2 at 25 °C. Compare your answer to the actual ΔH° f given in Appendix B, and explain why your calculation is only an estimate.676views
Open QuestionEthanol is a possible fuel. use average bond energies to calculate δHrxn for the combustion of ethanol. CH3CH2OH(g) + 3 O2(g) → 2 CO2(g) + 3 H2O(g)183views
Open QuestionCalculate the average molar bond enthalpy of the carbon–hydrogen bond in a CH4 molecule.196views
Open QuestionUse average bond energies to calculate δHrxn for the following hydrogenation reaction: H2C=CH2(g) + H2(g) → H3C−CH3(g)172views
Open QuestionCalculate δhrxn for the combustion of octane (C8H18) by using average bond energies.153views
Open QuestionUse average bond enthalpies to estimate the enthalpy δhrxn of the following reaction: 2 SF4(g) + O2(g) → 2 OSF4(g)231views
Open QuestionEthanol is a possible fuel. use average bond energies to calculate δHrxn for the combustion of ethanol.212views
Open QuestionEthanol is a possible fuel. Use average bond energies to calculate δHrxn for the combustion of ethanol. CH3CH2OH(g) + 3 O2(g) → 2 CO2(g) + 3 H2O(g)182views