Question

Intermolecular hydrogen bonding is not present in which of the following pairs of molecules?

• A. $Si{H}_4$ and $Si{F}_4$
• B.
• C.
• D. All have intermolecular H-Bonding

Answer 1

The correct option is A $Si{H}_4$ and $Si{F}_4$

Intermolecular hydrogen bonding is formed between the hydrogen atom (attached to an electronegative atom) of one molecule and an electronegative atom of another molecule.
(a)

As the electronegativity of $Si$ is less than that of $H$, the $H$ atom does not have a partial positive charge here instead, it will have a partial negative charge. So, there would not be any H-bond formation between $H$ and $F$.

(b) $CHC{l}_3$ and $C{H}_{3}COC{H}_3$


(c)
In both (b) and (c) there is intermolecular hydrogen bonding. Hence option (a) is the correct answer.