The boiling point of CCl4 is higher than SiCl4. CCl4 has Vander
waal forces as well as SiCl4 has but the b.p of SiCl4 is expected
to be higher than CCl4 as the former has more spacious electron
cloud. Can someone explain.
I actually posted the answer to this question on my BedokFunland JC
website several years ago :
Due to the greater magnitude of electronegativity difference
between Si and Cl, compared to C and Cl, there is a larger
magnitude of partial negative charge on the Cl atoms in SiCl4
molecules (compared to CCl4 molecules), and consequently a greater
extent of electrostatic van der Waals repulsions between SiCl4
molecules, and therefore SiCl4 has a lower boiling point, compared
to CCl4.
