Boiling point of HF is greater than HCl. Give reason.

The boiling point of hydrofluoric acid (HF) is higher than that of hydrochloric acid (HCl) due to the presence of hydrogen bonding in HF.

Key Factors Influencing Boiling Points

Several factors contribute to the boiling points of substances, including molecular weight, intermolecular forces, and molecular structure. In the case of HF and HCl, the differences in their molecular interactions play a crucial role.

Hydrogen Bonding in HF

HF molecules can form strong hydrogen bonds because of the highly electronegative fluorine atom. This leads to a significant attraction between HF molecules, requiring more energy (in the form of heat) to break these bonds during boiling.

Weaker Interactions in HCl

On the other hand, HCl does not exhibit hydrogen bonding to the same extent. The chlorine atom is less electronegative than fluorine, resulting in weaker dipole-dipole interactions. Consequently, HCl molecules require less energy to separate, leading to a lower boiling point.

Summary

• HF: Higher boiling point due to strong hydrogen bonding.
• HCl: Lower boiling point due to weaker intermolecular forces.

In summary, the stronger hydrogen bonds in HF compared to the weaker interactions in HCl account for the difference in their boiling points.