Gaseous iodine pentafluoride, IF5, can be prepared by the reaction of gaseous iodine and gaseous fluorine according to the following balanced equation:

I2(𝑔)+5 F2(𝑔)→2IF5(𝑔)

a. The value of Δ𝐻𝑓° for IF5(𝑔) is − 843 kJ/mol. Using this value and data in Appendix C, calculate Δ𝐻° for the preceding reaction.

b. The IF5 molecule has five I—F single bonds. Use your answer to part (a) and data in Table 5.4 to estimate the bond enthalpy 𝐷(I—F).