Choose the most polar bond from the options given below.

Question

a) B-O
b) B-S
c) C-N
d) C-O

Answer 1

Look up the electronegativity of each atom and subtract them. The most polar bond will be the one with the largest difference.
Example:
for d. C is approximately 2.5 and O is approx 3.5. Diff is 1.0
For C. C approx 2.5 and N approx 3.0 for diff of 0.5 so CO bond is more polar than CN bond.

Answer 2

B-O