The trends physical and chemical properties of chlorides depend on the position of the other element in the periodic table and its oxidation state.
Chlorides of metals in the +1 or +2 oxidation state are ionic solids.
Ionic solids are in general high melting (>300 °C) and exist as lattices where each anion is surrounded by cations AND each cation is surrounded by anions.
Potassium chloride is shown as an example of such a chloride. The lattice structure for potassium chloride is shown at the right. The brown spheres are chloride ions.
Ionic solids such as potassium chloride simply dissolve in water, dissociating to their ions. The ionic solid is then recovered if the solution is evaporated.
These halides are liquids or low melting solids and are hydrolysed in excess water to give hydroxides in the same oxidation state as the central element or oxoacids containing the element in the same oxidation state.
PCl3 is an example of such a chloride. The structure of PCl3 molecules is shown at the right.
PCl3 reacts with water according to the reaction below.
Chlorides of metals in the +1 or +2 oxidation state are ionic solids.
Ionic solids are in general high melting (>300 °C) and exist as lattices where each anion is surrounded by cations AND each cation is surrounded by anions.
Potassium chloride is shown as an example of such a chloride. The lattice structure for potassium chloride is shown at the right. The brown spheres are chloride ions.Ionic solids such as potassium chloride simply dissolve in water, dissociating to their ions. The ionic solid is then recovered if the solution is evaporated.
KCl(s) + H2O 
K+(aq) + Cl–(aq)
Chlorides of semimetals, nonmetals and metals in higher oxidation states in general exist as molecules due to the covalent bonding between the central element and chlorine. K+(aq) + Cl–(aq)These halides are liquids or low melting solids and are hydrolysed in excess water to give hydroxides in the same oxidation state as the central element or oxoacids containing the element in the same oxidation state.
PCl3 is an example of such a chloride. The structure of PCl3 molecules is shown at the right.PCl3 reacts with water according to the reaction below.
PCl3 + 3H2O P(OH)3 (also written as H3PO3) + 3HCl
P(OH)3 (also written as H3PO3) + 3HCl