Answer :
(1) [tex]I_2[/tex] act as a reducing agent and [tex]Cr_2O_7^{2-}[/tex] act as a oxidizing agent.
(2) [tex]As_2O_3[/tex] act as a reducing agent and [tex]NO_3^{-1}[/tex] act as a oxidizing agent.
Explanation :
Reducing agent : It is defined as the agent which helps the other substance to reduce and itself gets oxidized. Thus, it will undergo oxidation reaction.
Oxidizing agent : It is defined as the agent which helps the other substance to oxidize and itself gets reduced. Thus, it will undergo reduction reaction.
(1) [tex]Cr_2O_7^{2-}+I_2\rightarrow Cr^{3+}+IO_3^{-1}[/tex]
In this reaction, 'I' is oxidized from oxidation (0) to (+5) and 'Cr' is reduced from oxidation state (+6) to (+3). Hence, [tex]I_2[/tex] act as a reducing agent and [tex]Cr_2O_7^{2-}[/tex] act as a oxidizing agent.
(2) [tex]As_2O_3+NO_3^{-1}\rightarrow H_3AsO_4+N_2O_3[/tex]
In this reaction, 'As' is oxidized from oxidation (+3) to (+5) and 'N' is reduced from oxidation state (+5) to (+3). Hence, [tex]As_2O_3[/tex] act as a reducing agent and [tex]NO_3^{-1}[/tex] act as a oxidizing agent.