Q13P Explain why HCI has a smaller di... [FREE SOLUTION]

Chapter 1: Q13P (page 2)

Explain why HCI has a smaller dipole moment than HF,even though the H -CI bond is longer than the H-F bond.

Short Answer

Expert verified

HF has a larger electronegativity difference compared to that of HCI and thus it has a smaller dipole moment despite its longer bond length.

Step by step solution

Understanding the Dipole Moment and its relation with bond length and electronegativity

The dipole moment is a vector quantity measured in terms of electronegativity. It is the measurement of separation of two opposite charges.

With the increase in electronegativity, the difference in dipole moment of a molecule increases. With the increase in bond length, the dipole moment of a molecule increases.

Comparing HF and HCI

Fluorine is more electronegative than chlorine thus, the electronegativity difference of HF is more compared to HCI .

On the other hand, the bond length is greater in the case of H-CI compared to H-F.

Bond length 鈭� 1/鈻矱N

Here, 鈻矱N is the electronegativity difference between the two atoms. The higher difference in electronegativity overcomes the bond length factor thus giving the H-F molecule a greater dipole moment than HCl.