A molecule with many O-H bonds is likely to be more polar than a molecule with many C-H bonds. True or false?

A molecule with many O-H bonds is likely to be more polar than a molecule with many C-H bonds. True or false?

• A. False
• B. Not related
• C. Depends on molecular weight
• D. True

Answer: (D)

Polarity of a molecule is governed by the distribution of electric charge, which comes from differences in electronegativity and how the bond dipoles sum up in the molecule. An O-H bond is highly polar because oxygen is much more electronegative than hydrogen, pulling electron density toward itself and creating a strong bond dipole. In contrast, a C-H bond has only a small electronegativity difference, giving a much weaker dipole. When a molecule has many O-H bonds, these strong dipoles add together to produce a larger overall dipole moment, making the molecule more polar. Hydrogen bonding tendencies also reinforce this effect. While molecular geometry can influence whether dipoles cancel out, the presence of many O-H bonds generally leads to greater polarity. Therefore, the statement is true.

Polarity of a molecule is governed by the distribution of electric charge, which comes from differences in electronegativity and how the bond dipoles sum up in the molecule. An O-H bond is highly polar because oxygen is much more electronegative than hydrogen, pulling electron density toward itself and creating a strong bond dipole. In contrast, a C-H bond has only a small electronegativity difference, giving a much weaker dipole. When a molecule has many O-H bonds, these strong dipoles add together to produce a larger overall dipole moment, making the molecule more polar. Hydrogen bonding tendencies also reinforce this effect. While molecular geometry can influence whether dipoles cancel out, the presence of many O-H bonds generally leads to greater polarity. Therefore, the statement is true.