In the compound CoCl<sub>2</sub>6H<sub>2</sub>O, we have three different elements: cobalt Co , chlorine Cl , and hydrogen H and oxygen O in the water molecules.1. Cobalt Co : In CoCl<sub>2</sub>, the oxidation state of chlorine is -1 as a halogen, it usually has an oxidation state of -1 . Since there are two chlorine atoms, the total negative charge from chlorine is -2. To balance the charge, the oxidation state of cobalt must be +2. So, the oxidation state of Co is +2.2. Chlorine Cl : As mentioned earlier, the oxidation state of chlorine in CoCl<sub>2</sub> is -1.3. Hydrogen H : In the water molecules H<sub>2</sub>O , hydrogen is bonded to oxygen. Hydrogen typically has an oxidation state of +1 when bonded to nonmetals. So, the oxidation state of H is +1.4. Oxygen O : In the water molecules H<sub>2</sub>O , oxygen is bonded to hydrogen. Oxygen typically has an oxidation state of -2 when bonded to nonmetals. So, the oxidation state of O is -2.In summary, the oxidation states of the elements in CoCl<sub>2</sub>6H<sub>2</sub>O are:- Cobalt Co : +2- Chlorine Cl : -1- Hydrogen H : +1- Oxygen O : -2