Question

In which compound, the hydrogen bonding is the strongest in its liquid phase?
A) HF
B) HI
C) \[{\rm{C}}{{\rm{H}}_{\rm{4}}}\]
D) \[{\rm{P}}{{\rm{H}}_{\rm{3}}}\]

Answer 1

Hint: A hydrogen bonding is the bond of hydrogen with electronegative atoms like nitrogen, oxygen and fluorine. The strength of a hydrogen bonding is less than an electrovalent bond.

Complete step by step solution:Let’s discuss all the options one by one.
Option B is HI. The hydrogen bond is formed between electronegative atoms such as nitrogen, oxygen and fluorine and hydrogen. Here, no hydrogen bond forms.
Option C is \[{\rm{C}}{{\rm{H}}_{\rm{4}}}\]. There will be no hydrogen bond formation in methane because there is no presence of polar bond in the molecule. The polar bond is present when there is a very large difference of electronegativity of the atoms. The electronegativity of Carbon and hydrogen is not much.
Option C is \[{\rm{P}}{{\rm{H}}_{\rm{3}}}\]. The size of the phosphorus molecule is large and also its electronegativity is less. So, no polar bond is formed in the reaction. Therefore, hydrogen bonds are not present in \[{\rm{P}}{{\rm{H}}_{\rm{3}}}\].
Option A is HF. We know that fluorine is the most electronegative atom and it has the smallest size. Therefore, it forms the hydrogen bond. Therefore, HF has the strongest H bond.

Hence, option A is right.

Note: Always remember that four types of bond present. Their names are ionic bond, covalent bond, hydrogen bond and van der waals interaction. The strength of van der waals force is the lowest and the strength of ionic and covalent bonds are highest. And the strength of the H bond lies in the middle.