Despite the large difference in electronegativity between #"Si"# and #"F"#, #"SiF"_4# has a boiling point lower than that of #"NH"_3# (#-86^@ "C"#, vs. #-33^@ "C"#). Why is that? Could it be due to the symmetry? Hydrogen-bonding?
Note: the #"Si"-"F"# bond length is #"155.4 pm"# , and the #"N"-"H"# bond length is #"101.2 pm"# .
Note: the
1 Answer
There are two answers
1.) Because of the hydrogen bonds (precisely interactions)
2.) Because of the tetrahedral arrangement of Si-F
Explanation:
Though the large difference in electronegativity between
This is because that boiling is completely dependent on intermolecular forces and not on intramolecular forces.
And in
Because that London Dispersion Forces are temporary because electron density is always changing all across the atom dipole-dipole forces are much stronger because they are permanent and always in alignment.
Despite the large difference in electronegativity between
And more stronger the intermolecular force more the boiling point