Question

Which of the bonds in Problem 9.84 is the most polar?

Short answer

The N-S bond is the most polar bond.

Step-by-step solution

Bond polarity

Polarity of a bond increases as the electronegativity difference between the atoms increases

The electronegativity difference in N-S bond is$\mathbf{(}\mathbf{3}\mathbf{.}\mathbf{1}\mathbf{-}\mathbf{2}\mathbf{.}\mathbf{4}\mathbf{)}=\mathbf{0}.\mathbf{7}$

The electronegativity difference in Si - I bond is$\mathbf{(}\mathbf{2}.\mathbf{2}-\mathbf{1}.\mathbf{8}\mathbf{)}=\mathbf{0}.\mathbf{4}$

The electronegativity difference in N- Br bond is$\mathbf{(}\mathbf{3}.\mathbf{1}-\mathbf{2}.\mathbf{8}\mathbf{)}=\mathbf{0}.\mathbf{3}$

The electronegativity difference in C – Cl bond is$\mathbf{(}\mathbf{2}.\mathbf{9}-\mathbf{2}.\mathbf{5}\mathbf{)}=\mathbf{0}.\mathbf{4}$

Most polar bond

The electronegativity difference in N-S bond is maximum among the four at = (3.1-2.4) = 0.7

The N-S bond is most polar.