Embibe Experts Solutions for Chapter: Redox Reactions, Exercise 3: Exercise-3

Reaction of ${\mathrm{Br}}_2$ with ${\mathrm{Na}}_2{\mathrm{CO}}_3$ in aqueous solution gives sodium bromide and sodium bromate with evolution of ${\mathrm{CO}}_2$ gas. The number of sodium bromide molecules involved in the balanced chemical equation is 

Consider the following reaction:
${\mathrm{xMnO}}_4^{-}+{\mathrm{yC}}_2{\mathrm{O}}_4^{2-}+{\mathrm{zH}}^{+}\to {\mathrm{xMn}}^{2*}+2{\mathrm{yCO}}_2+\frac{\mathrm{z}}{2}{\mathrm{H}}_2\mathrm{O}$
The values of $\mathrm{x}, \mathrm{y}$ and $\mathrm{z}$ in the reaction are, respectively:

Among the given reactions, Which reaction is an example of a redox reaction?
 

Among the following, the number of elements showing only one non-zero oxidation state is $\mathrm{O}, \mathrm{F}, \mathrm{Cl}, \mathrm{N}, \mathrm{P}, \mathrm{Sn}, \mathrm{Tl}, \mathrm{Na}, \mathrm{Ti}$.
 

In basic medium, ${\mathrm{I}}^{-}$ is oxidised by ${\mathrm{MnO}}_{4^{-}}^{}.$ In this process, ${\mathrm{I}}^{-}$ changes to:

When ${\mathrm{KMnO}}_4$ acts as an oxidising agent and ultimately forms ${\mathrm{MnO}}_4^{2-}, {\mathrm{MnO}}_2, {\mathrm{Mn}}_2{\mathrm{O}}_3$ and ${\mathrm{Mn}}^{2+},$ then determine the number of electrons transferred in each case.

Which ordering of compounds is according to the decreasing order of the oxidation state of nitrogen?                                                                                                            

Consider the following list of reagents: Acidified ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7,$ alkaline ${\mathrm{KMnO}}_4,$ ${\mathrm{CuSO}}_4,$ ${\mathrm{H}}_2{\mathrm{O}}_2,$ ${\mathrm{Cl}}_2$, ${\mathrm{O}}_3$, ${\mathrm{FeCl}}_3$, ${\mathrm{HNO}}_3$. The total number of reagents that can oxidise aqueous iodide to iodine are