Is this reaction oxidation or reduction?

Question

CaCl2(s) --> Ca2+(aq) + 2Cl-(aq)

Answer 1

Favorite Answer

No, neither. It is simply the dissociation of solid calcium chloride into ions. Oxidation is an increase in the oxidation number of an element, while reduction is a decrease in the oxidation number. These may be accompanied by actual exchanges of electrons. In the case of CaCl2, the calcium has the same oxidation state that is assigned to the Ca2+ ion in solution. Nor does the chlorine change oxidation state. Therefore, no redox has occurred.

=========== Follow up =============

It is indeed dissociation, or ionization, but it is not oxidation and reduction as Abhijith suggests. That would require Ca and Cl to have different oxidation states in solid CaCl2 than they do as ions. In solid CaCl2, Ca is assigned an oxidation state of +2 and chlorine an oxidation state of -1. As ions, Ca2+ has an oxidation state of +2, and Cl- has an oxidation state of -1. No changes in oxidation state, and no oxidation or reduction.

Answer 2

neither one, and its not a reaction - it just depicts CaCl2 dissolving in water

Note : a reaction cannot be oxidation or reduction - both must occur simultaneously in these reactions.

Answer 3

Same thing as with barium chloride; it is just dissociation.