Is bond strength inversely proportional to bond length? As the bond length decreases, does the bond strength increase?
1 Answer
Decrease in bond length and increase in strength is only a trend, that is observed only between the same pairs of atoms, so its approximately true for C C bonds, single, double triple and similarly for N N bonds. But in general this is not true as can be seen in the following list of bonds with approximately the same length e.g.
$\ce{H-Br,141 pm 366} \pu{ kJ mol^{-1}}$
$\ce{F-F, ~142 , ~~~~158}$
$\ce{C-O, 143 , ~~~~360}$
$\ce{O-O, 148 , ~~~145}$
$\ce{N-N, 145 , ~~~170}$