Question

Compare the bond lengths (x and y) in the following molecules:

• A. $x>y$
• B. $y>x$
• C. $x=y$
• D. None of these

Answer 1

The correct option is B $y>x$

Lone pairs have more $\%s$ character than the multiple bonds. Hence, orbitals having lone pairs have more $\%s$ character and the other orbitals have less $\%s$ character.

$\%s\downarrow$ bond length $\uparrow$

Therefore, sulphur fluorine bonds in $S{F}_4$ should have a lower $s$ character compared to the ones in $SO{F}_4$. Since $S{F}_4$ has a lower $s$ character, its bond length will be higher than the one in $SO{F}_4$.