Question

3. Stability of Axial vs. Equatorial Lone-Pairs in Trigonal Bipyramidal Structures: SF. Useful conversion factors: o 1 au = 627.5096 kcal/mol = 2,625 50 kJ/mol a. Based on the Spartan data, which structure of SF. is more stable? (Circle one.) SF. w/ lone pair in axial position (SF, w/ lone pair in equitorial position How do you know which is more stable? more neseline value = more Shtle b. Energy of the axial lone-pair structure in au)? - 795.098 AU c. Energy of the equatorial lone-pair structure (in au)? -73.143396 AU d. Calculate the overall energy difference (in kJ/mol between the two forms of SF. OF -- 6795.0893100)- 6-715-(49abav) ---1550060W -144.418253 kJ/mol e. Do these relative energies seem reasonable based on the VSEPR theory? Explain which confirmation is more stable and why (based on VSEPR).
letter e please

Answer 1

According to VSEPR,the Structure with Equitorial l.p. should be more stable, and thus it should have the more negative value, but your data reveals the opposite situation.So, the relative energies don't seem reasonable according to VSEPR. According to Bent's Rule, in a TBP Structure, the more electronegative atom will always occupy the Axial position, due to the greater p-character enriched orbitals(low Electronegativity) of Central Atom, thus the 2 Axial positions in SF_{​​​​​4} will always be occupied by F, and the l.p. will remain in the Equitorial position, in a orbital with greater s-character(higher Electronegativity). The l.p. is of S, thus S will always tend to hold it strongly, thus housing it in an orbital with greater s-character, in the Equitorial Position.