[Mal1ce]

IO₃^- + I^- + Cl^-  ICl₂^-

So I am trying to balance this equation but I don't know how to assign the oxidation number for ICl₂^-. Is the Cl₂ 0 and I -1?

[Hybrid]

no in this case I +1 and Cl -1 electronegativity .

that is called andrewss method for assay of iodide

as you write your equation balance will be like that

IO3- + I- + Cl-  _______  ICl2-

(I+5 O-6) -   +2 I-  + 6Cl- ____+  6H+ _________ 3(I+1 Cl-2) -  + 3H2O

but actually don't add Cl- to formed ICl = ICl2-

IO3- + 2I- + 6HCl ---> 3ICl + 3Cl- + 3H2O

[Mal1ce]

Thank you.