Question

AlF3 is a high melting point solid whereas SiF4 is a gas?

Answer 1

AlF₃ is a ionic compound, in which there is a high electroneagativity difference between Aluminium and fluorine, So there is high electrostatic force in this molecule, thus the molecule exists as a high melting solid while SiF₄, is a covalent compound, in which they are weak vander waal forces thus it exists as a gas. So AlF3 is a high melting point solid whereas SiF4 is a gas.

Answer 2

hi,

AIF3 is an ionic compound where electrostatic forces of attraction is present. Whereas SiF4 is a gas because it has covalent bond in them...

Hope it helps you !