Note to Students Bond dissoclation energies are experimental values and have associated uncertainties. Values will differ slightly from source to source. For OWL to judge your answer correct, you must use the values-from the OWL Table Reference (click the References button and then click the Tables link on the drop-down that appears). I. Two Kinds of Bond Energies Bond dissociation energy, symbol D, is the minimum enthalpy required to break a specific bond in a specific molecule. Average bond energy, symbol E, is the "average" strength of one type of bond in many molecules. Both apply to gas-phase bond fission to produce radicals (not lons) and are tabulated on molar basis. In favorable cases, bond dissociation energies can be measured to high accuracy; while, by their nature, average bond energies are approximations. This question deals with bond dissociation energles. The enthalpy criterion for whether a reaction can proceed is given in section III B below. A. Bond Dissociation Energies Bond dissociation energles are defined at a specific temperature, usually 298K(25C) and are given the symbol D. Bond dissociation energies for one type of bond can span a substantial range, e.g. H3CHCH3CH2H(CH3)2CHH(CH2)3CHH2C=CHCH2HD=439k//molD=420kJ/molD=401kJ/molD=390kJ/molD=361kJ/mol Use the References to access important values if needed for this question. For the reaction below: CH3CH2+nBu3SnHCH3CH2H+nnu3Sn. a. Estimate the gas phase enthalpy change using bond dissociation enthalples from the OWL Table Reference, not data from your text. Click the References button and then click the Tables link on the dropdown that appears. Include aigebraic sign and units. b. Is the reaction exothermic or endothermic? c. Is the reaction likely to proceed spontaneously in the direction written