Q9.87CP - Chemistry: Molecular Nature Of Matter And Change

Question

Which of the bonds in the Problem 9.85 is the least polar?

Step-by-Step Solution

Answer

The Si-F bond is least polar bond.

Step 1: Bond Polarity

Polarity of a bond decreases as the electronegativity difference between the atoms decreases. 

 

The electronegativity difference in Hg-I bond is $\mathbf{(}\mathbf{2}.\mathbf{2}-\mathbf{1}.\mathbf{5}\mathbf{)}=\mathbf{0}.\mathbf{7}$

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

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

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

Step 2: Least polar bond

The electronegativity difference in Si-F bond is minimum among the four at = (2.2-2.1) = 0.1 

 

The Si-F bond is least polar bond.