Can we call `Al_2O_3` and ZnO acidic oxides on the basis of these reactions?

Al_2O_3 is an amphoteric oxide.

In the reaction between chlorine and HBr transformation of HBr into Br_2 takes place. Can this transformation be called oxidation? Which is the oxidant that brings about this oxidation?

Acidity of BF_3 can be explained on the basis of which of the following concepts?

The oxidant and the reductant species resectively of the reactants in the reaction Br_2 + OH^- rarr Br^(-) + BrO_3^(-)+ H_2O

While sulphur dioxide and hydrogen peroxide can act as oxidising as well as reducing agents in their reactions, ozone and nitric acid not only as oxidants. Why?

3MnO_2 + 4Al to 3Mn + 2Al_2O_3 + Heat Identify the substances undergone oxidation and reduction in this reaction

Answer the following questions: 3MnO_2+ 4Alrarr 3 Mn+ 2Al_2O_3 + heat . Identify the substances undergone oxidation and reduction reactions.

What is the change in oxidation number of chlorine in the following reaction? 2H_2O_2 +ClO_4^(-)rarr2O_2+ClO_2^(-)+2H_2O

How is the transformation of ethanol into ethanoic acid an oxidation reaction?