In the chromyl chloride test,the oxidation state of $Cr$ changes from:

When $KMnO_4$ acts as an oxidising agent and ultimately forms $[MnO_4]^{2-}$,$MnO_2$,$Mn_2O_3$,and $Mn^{2+}$,the number of electrons transferred in each case respectively is:

What is the change in oxidation number of nitrogen in the following conversion? $NO_3^{-} \longrightarrow NO_2$

Given below are two statements.
Statement $I$ : In $H_2O_2$, each oxygen atom is assigned an oxidation number of $-1$, and in $RbO_2$, each oxygen atom is assigned an oxidation number of $-\frac{1}{2}$.
Statement $II$ : The representation of $HAuCl_4$ and $MnO_2$ in Stock notation is $HAu(III)Cl_4$ and $Mn(IV)O_2$ respectively.
Examine the above statements and choose the correct answer.

Oxidation state of nitrogen in nitric oxide is

The oxidation number of fluorine in $F_2O$ is