80) Which one of the following should have the lowest boiling point? Group of answer choices HCl H2S PH3 H2O SiH4

SiH4

Explanation:

We must remember that the magnitude of intermolecular forces play a vital role in the determination of the boiling point of a substance.

The Si-H bond is the least polar among all the bonds in compounds listed in the question. This is because the electronegativity difference between silicon and hydrogen is very slim resulting in the formation of a nonpolar covalent bond.

The other compounds possess more polar bonds hence have a greater degree of dipole interaction between molecules and a consequently higher boiling point than SiH4.