Rank the bonds from most polar to least polar. a) C-O, C-F, C-N
b) C-CI, C-I, C-Br
c) H-O, H-N, H-C
d) C-H, C-C, C-N

Answers are in the explanation.

Explanation:

Polarity of a bond is due difference in electronegativity of the atoms that are bonding. The highest difference, the most polar bond.

Electronegativities:

O: 3.5

F: 4.0

N: 3.0

Cl: 3.0

I: 2.5

Br: 2.8

H: 2.1

C: 2.5

a)

Difference in electronegativity:

C-O = |2.5 - 3.5| = 1

C-F = 1.5

C-N = 0.5

The ranking is: C-F, C-O, C-N

b)

C-Cl = 0.5

C-I = 0

C-Br = 0.3

Ranking: C-Cl, C-Br, C-I

c)

H-O = 1.4

H-N = 0.9

H-C = 0.4

Ranking: H-C, H-N, H-O

d)

C-H = 0.4

C-C = 0

C-N = 0.5

Ranking: C-N, C-H, C-C