Question

Part IV: Bond Energy and Bond Length The strength of a covalent bond is measured by the bond energy. There are tables of average bond energies in your textbook. It is important to remember that these values represent average bond energies. For example, a table may give a value of 745 kJ/mol for C-O, but the actual value in Co, is 799 kJ/mol. Therefore any calculations using these values will only be approximate, The length of a covalent bond is usually defined as the equilibrium distance between the nuclei, Some bond length and strength data are below. Energy (kJ/mol) Bond Length (pm) Н-F 565 427 363 92 127 Н-CI Н-Br 141 161 154 134 Н-1 295 С-С 347 С-С С-С 614 839 121 1. What is the relationship between bond strength and bond length? Give examples from the table to support your answer. 2. How does the bond order, number of shared pairs, affect the strength? relationship? Give examples from the table to support your answer. Is it a linear 3. Lewis structures and tables of bond energies can be used to estimate (why estimate?) values of AHran for reactions. Use bond energies from your textbook to calculate the enthalpy of combustion of one mole of C2 Hs (g) where all reactants and products are gases. Write out the steps/information necessary to solve this problem and then carry them out.

Answer 1

) Bond strengen of Bond lengen Example 2 H-F Au are Hace 4-Bh H-1 - Bond lengan increases → Bond energy de eneones (As give I single bond) in the Bond strength of Frompu from the tables Bond onden. Bond energy onders C= c) c = c) c-c ( CHb 7702 - 2002 + 3H20 - (1) 4h can be calculated from bond energy xalwes. For ands we need caleviate total bond energy a products & total bond enen y reactan . Then we need to subst bond energy I reactant from bond energy of product Lewis dot fructure indicates types of bonds & table given connesponding bond energy. So Lewis structures & tables of bond energy con be used to estima 4 Horon : To calculate Athryn of (d) we need to follow these steps - 6) Lewis structure of reactants & Products. il Identity the types of bonds. Find out bond energy values... Find out in som total energy of racts & total bond enangy of product .

row substract frral bond energy reactant from total bond energy of Prodyets.