According to Laurens the reaction is as follows:--

_a._ 2CuCl_{2} = Cl_{2} + 2Cu_{2}2Cl_{2}.

_b._ Cu_{2}Cl_{2} + 2HCl + O = H_{2}O + 2CuCl_{2}.

6. MacDougal, Rawson, and Shanks. This is effected by decomposing chromate

of lime by means of hydrochloric acid, the result being the formation of

chloride of chromium, chloride of calcium, and the evolution of free

chlorine; thus