Boiling Point

[ayushibanerjee06]

Does SiH4 or SiF4 have a higher boiling point?

[Hiba Alnajjar_2C]

SiF4 would have a higher boiling point. Because F is larger than H and contains more electrons, it is more polarizable. Because it is more polarizable, its electrons are more easily distorted, meaning its London Dispersion forces are stronger than that of SiH4. Because of these stronger intermolecular forces, it will take more energy to boil SiF4 than SiH4, therefore it has a higher boiling point.

[Daniel Honeychurch1C]

SiF4 (-86 C) has a higher boiling point than SiH4 (-112 C). SiF4 is larger and has more electrons, making it more polarizable. This increases the induced dipole-induced dipole forces.

[anjali41]

SiF4 would have a higher boiling point than SIH4 even though their Lewis structures look similar. This is due to the fact that Fluorine has a larger mass, which indicates more electrons than Hydrogen. Thus, it is more polarizable and has stronger intermolecular forces.

[805097738]

so electrons with more electrons have stronger London forces?

[Baoying Li 1B]

London dispersion forces depend on the mass of a molecular. The greater the mass, the greater the forces.
Boiling point increases due to the increasing molar masses, increasing surface tension, increasing intermolecular forces.
Also, larger polarity results in greater intermolecular attractive forces.
Since SiF4 has a greater molecular mass than SiH4, therefore SiF4 has a greater London dispersion force and a greater boiling point.

[bellaha4F]

when the surface area increases, there's more room for temporary induced dipole interactions to occur, therefore more LDFs, therefore a higher boiling point.

[HuyHa_2H]

Both SiH4 and SiF4 are nonpolar which mean that they only display LDF forces. So when both molecules have LDF you look at the size. The F is more bigger than H so SiF4 is the bigger one of the two which makes it have stronger LDF forces so higher boiling point.