Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$MnO_2 + 2NaCl + 2H_2SO_4 \longrightarrow MnSO_4 + Na_2SO_4 + 2H_2O + Cl_2 \uparrow$

Oxidation of thiosulphate $S_2O_3^{2-}$ ion by iodine gives

For the reaction $P_4 + xOH^- + yH_2O \to PH_3 + H_2PO_2^-$,determine the correct relationship between $x$ and $y$.

For the reaction $Cr_2O_7^{2-} \xrightarrow{H^+} Cr^{3+}$,what is the equivalent weight of $Cr_2O_7^{2-}$?

Consider the reactions:
$(a)$ $6CO_{2(g)} + 6H_2O_{(l)} \to C_6H_{12}O_{6(aq)} + 6O_{2(g)}$
$(b)$ $O_{3(g)} + H_2O_{2(l)} \to H_2O_{(l)} + 2O_{2(g)}$
Why is it more appropriate to write these reactions as:
$(a)$ $6CO_{2(g)} + 12H_2O_{(l)} \to C_6H_{12}O_{6(aq)} + 6H_2O_{(l)} + 6O_{2(g)}$
$(b)$ $O_{3(g)} + H_2O_{2(l)} \to H_2O_{(l)} + O_{2(g)} + O_{2(g)}$
Also,suggest a technique to investigate the reaction mechanism (path) of the above $(a)$ and $(b)$ redox reactions.

Assign $A, B, C, D$ from the given type of reaction.
$Sn + PCl_5 \xrightarrow{\Delta} SnCl_4 + PCl_3$