Answer:
Step-by-step explanation:
I₂ + 2 e = 2I⁻
I₂ converts itself into I⁻ by accepting electron . In this process it increases the oxidation number of element from which it takes electron . Hence it is an oxidizing agent .
Similarly O₂ is also an oxidizing agent .
O₂ + 4e = 2O⁻²
Al is a reducing agent .
Al = Al⁺³ + 3 e
Al gives 3 electrons to other element whose oxidation number is reduced . Hence it is reducing agent .
Similarly Cr is also a reducing agent .
Cr = Cr⁺³ + 3 e .