The standard molar enthalpies of formaton of ${\mathrm{IF}}_3 \left(\mathrm{g}\right)$ and${\mathrm{IF}}_5\left(\mathrm{g}\right)$ are $-470 \mathrm{kJ}$ and $-847 \mathrm{kJ},$ respectively. Valence shell electron-pair repulsion theory predicts that ${\mathrm{IF}}_3\left(\mathrm{g}\right)$) is square pyramidal in shape in which all $\mathrm{I}-\mathrm{F}$ bonds are equivalent while ${\mathrm{IF}}_3 \left(\mathrm{g}\right)$is $\mathrm{T}$-shaped (based on trigonal-bipyramidal geometry) in which $\mathrm{I}-\mathrm{F}$ bonds are of different lengths. It is observed that the axial$\mathrm{I}-\mathrm{F}$bonds in ${\mathrm{IF}}_3$ are equivalent to the $\mathrm{I}-\mathrm{F}$ bonds in ${\mathrm{IF}}_5$ • Calculate the equatorial $\mathrm{I}-\mathrm{F}$ bond strength (in kJ/mol) in $\mathrm{IF}$ 3 • Some other information's given are :

${\mathrm{I}}_2\left(s\right)⟶{\mathrm{I}}_2\left(\mathrm{g}\right);\mathrm{\Delta }H=62\mathrm{kJ}$

${\mathrm{F}}_2\left(g\right)⟶2{\mathrm{F}}_{\left(g\right)};\mathrm{\Delta }H=155\mathrm{kJ}$

${\mathrm{I}}_2\left(\mathrm{g}\right)⟶2\mathrm{I}\left(\mathrm{g}\right);\mathrm{\Delta }H=149\mathrm{kJ}$