Why does magnesium chloride have a much higher melting point than hydrogen chloride?
Magnesium chloride is a neutral solid salt but hydrogen chloride is an acid gas. The chemical bonds in magnesium chloride are very strong ionic bonds in which the magnesium atom gives an electron to the chlorine atom so that they each have opposite electric charge and are drawn very closely and strongly together. The bonds in hydrogen chloride are covalent and much weaker because the elements do not exhange electrons so the atoms are not pulled together by electric forces.Thus the magnesium chloride is a high meltng point solid and thehydrogen chloride is a low freezing point gas.