Question

Contrary to other hydrogen halides, hydrogen fluoride is a liquid because:
A six of F atom is small
B HF is a weak acid
C HF molecule are hydrogen bonded
D Fluorine is highly reactive

Answer 1

Hint: Group 17 elements are known as halogens. These elements just need one more electron to achieve a perfect noble gas configuration. Out of all the halogens F is the most electronegative element, in fact F is the most electronegative element in the periodic table. Due to the small size of F, F can attract shared pairs of electrons towards itself effectively.

Complete step-by-step answer:A hydrogen atom that is bound to a highly electronegative atom and another highly electronegative atom that is close by interact with one another to form hydrogen bonds, which are an unique kind of attractive intermolecular interactions. This process is known as hydrogen bonding. For instance, in water molecules, hydrogen is covalently linked to the oxygen atom, which is more electronegative. Therefore, the dipole-dipole interactions between the hydrogen atom of one water molecule and the oxygen atom of another water molecule are what cause hydrogen bonding to form in water molecules.
Fluorine has a significant potential to gain electrons from other elements that have lower electronegativity because of its high electronegativity.
Fluorine has an electronegativity of 3.98.
Fluorine possesses five electrons in its 2p orbital, making it the most electronegative element. Since fluorine is so close to the optimum electron configuration for the 2p orbital, which has six electrons, the electrons are bound very securely to the nucleus.

Other group 17 elements can’t form hydrogen bonds as F. Thats why Contrary to other hydrogen halides, hydrogen fluoride is a liquid because HF molecule are hydrogen bonded.

Option ‘C’ is correct

Note: We are aware that group electronegativity diminishes from top to bottom. This is due to the fact that as the atomic number decreases within a group, the atomic radius—or the distance between the valence electrons and nucleus—increases.