Question

Rank the bonds from the most polar to least polar.

a. C - O,C - F,C - N

b. C - Cl > C - Br > C - I

c. H - O,H - N,H - C

d. C - H,C - C,C - N

Short answer

a. C-F>C-O>C-N

b. C-Cl>C-Br>C-I

c. H-O>H-N>H-C

d. C-N>C-H>C-C

Step-by-step solution

Defining bond polarity

The distribution of positive and negative electrical charge over a bond is known as bond polarity. The bond polarity can be determined by comparing the difference in electronegativity between the atoms. More the difference in electronegativity more polar is the bond.

Finding the order of polarity from most polar to least polar.

a. C-F>C-O>C-N

In the above series as the electronegativity order is F>O>N the bond polarity also increases with increase in electronegativity difference.

b. C-Cl>C-Br>C-I

Chlorine has the maximum electronegativity and iodine has the minimum electronegativity .Thus the polarity order is C-Cl>C-Br>C-I.

c. H-C

The electronegativity order varies as, O>N>C thus the bond polarity also increases with increase in electronegativity difference and H-O becomes the most polar while H-C becomes the least polar.

d. C-H

C-C does not have any electronegativity difference thus it is least polar .

In case C-H,C-N of nitrogen being more electronegative compared to hydrogen thus is C-N more polar compared to C-H.