When copper is heated with concentrated $HNO_3$,it produces:

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$I_2 + S_2O_3^{2-} \longrightarrow I^{-} + S_4O_6^{2-}$

In the following balanced chemical reaction,$IO_3^- + aI^- + bH^+ \to cH_2O + dI_2$,what are the values of $a, b, c$ and $d$ respectively?

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$Ag + PCl_5 \xrightarrow{\Delta} AgCl + PCl_3$

Explain intermolecular redox reaction with an example.

Reaction of $Br_2$ with $Na_2CO_3$ in aqueous solution gives sodium bromide and sodium bromate with evolution of $CO_2$ gas. The number of sodium bromide molecules involved in the balanced chemical equation is