Which bonds in caffeine are polar covalent bonds?
A) All of them
B) the C-N bonds only
C) the C=C, C-C and C-H bonds
D) the C-N, C=O, and C=N bonds
E) the O-H bonds

Question

Which bonds in caffeine are polar covalent bonds? 
A) All of them 
B) the C-N bonds only 
C) the C=C, C-C and C-H bonds 
D) the C-N, C=O, and C=N bonds 
E) the O-H bonds

Quizplus · Accepted Answer

Polar covalent bonds are formed when there is a difference in electronegativity between the two atoms within a bond. In caffeine, the C-N bond, C=O bond, and C=N bond all have a significant electronegativity difference and therefore are polar covalent bonds. The C=C, C-C, and C-H bonds have similar electronegativities and are therefore nonpolar. The O-H bonds are not present in caffeine.

Which Bonds in Caffeine Are Polar Covalent Bonds