Why doesn't SiCl4 conduct electricity when it's in its molten state and conducts electricity when water is added? The answer is C. I know very well what is X and Z, but unsure what is Y.. Why not Al2O3? What's the difference? Does it got to do with their structures? Al2O3 is ionic with a degree of covalent character whereas SiCl4 is a simple molecular? if so, what is the effect of it?