Chapter 18, Problem 8TE

Which bond is most polar:

(a) $\text{H}-\text{N}$

(b) $\text{N}-\text{C}$

(c) $\text{C}-\text{O}$

(d) $\text{C}-\text{C}$

(e) $\text{O}-\text{H}$

(f) $\text{C}-\text{H}$

To determine

The most polar bond.

Answer to Problem 8TE

The $\text{O}-\text{H}$ bond is the most polar.

Explanation of Solution

A polar bond is formed when the atoms are containing a difference in their electronegativities share their electrons. The atom which has higher electronegativity in the bond acquires a partial negative charge while the atom which has lower electronegativity in the bond acquires a partial positive charge.

The polarity of the bond depends on the difference between the electronegativities of atoms. More is the difference, more polar is the bond.

The electronegativity is a periodic trend. In the period it increases from left to right. The elements from left to right are C, N, O respectively. So, the O will be having the highest electronegativity. The H has the lowest electronegativity.

So, the bond between H and O will be the most polar.

Thus, the $\text{O}-\text{H}$ bond is the most polar.

Conclusion:

Therefore, the $\text{O}-\text{H}$ bond is the most polar.