Which one is the oxidising agent in the reaction below?
$2CrO_4^{2-} + 2H^{+} \to Cr_2O_7^{2-} + H_2O$

Match the following types of reactions in List-$I$ with their corresponding unbalanced equations in List-$II$.

List-$I$ (Type of reaction)	List-$II$ (Unbalanced equation)
$A$. Combination reaction	$(i)$ $AgNO_3 + CaCl_2 \longrightarrow AgCl + Ca(NO_3)_2$
$B$. Decomposition reaction	$(ii)$ $Cl_2 \longrightarrow Cl^- + ClO_3^-$
$C$. Disproportionation reaction	$(iii)$ $Mg + N_2 \longrightarrow Mg_3N_2$
$D$. Displacement reaction	$(iv)$ $KClO_3 \xrightarrow{\Delta} KCl + O_2$

Equivalent weights of $KMnO_4$ and $K_2Cr_2O_7$ in acidic medium are respectively. (Molecular weight of $KMnO_4 = M_A$ and Molecular weight of $K_2Cr_2O_7 = M_B$).

How many moles of $MnO_4^-$ are required to completely oxidize $1 \ mol$ of ferrous oxalate in an acidic medium?

When an acidic solution of $K_2Cr_2O_7$ is added to $Na_2SO_3$,it turns green. Which of the following compounds is formed in this reaction?

In order to oxidize a mixture of one mole of each of $FeC_2O_4$,$Fe_2(C_2O_4)_3$,$FeSO_4$ and $Fe_2(SO_4)_3$ in acidic medium,the number of moles of $KMnO_4$ required is