Which diagram correctly represents the change | vedclass

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(A) The aqueous solution of chromate ions ($CrO_4^{2-}$,yellow) changes to dichromate ions ($Cr_2O_7^{2-}$,orange) in an acidic medium $(2CrO_4^{2-} +

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(A) The aqueous solution of chromate ions ($CrO_4^{2-}$,yellow) changes to dichromate ions ($Cr_2O_7^{2-}$,orange) in an acidic medium $(2CrO_4^{2-} + 2H^+ \rightarrow Cr_2O_7^{2-} + H_2O)$.This orange dichromate solution can be reduced to green chromium$(III)$ ions $(Cr^{3+})$ using a reducing agent like $SO_2$ in an acidic medium $(Cr_2O_7^{2-} + 3SO_2 + 2H^+ \rightarrow 2Cr^{3+} + 3SO_4^{2-} + H_2O)$.The green $Cr^{3+}$ ions can be oxidized back to yellow chromate ions $(CrO_4^{2-})$ in an alkaline medium using an oxidizing agent like $H_2O_2$ $(2Cr^{3+} + 3H_2O_2 + 10OH^- \rightarrow 2CrO_4^{2-} + 8H_2O)$.Comparing these reactions with the given options,option $A$ correctly represents this cycle.

List-$I$ (Transition metal/Compound/complex)	List-$II$ (Catalytic Role)
$A$. $V_2O_5$	$I$. Preparation of ammonia from $N_2/H_2$ mixture
$B$. $Fe$	$II$. Polymerisation of alkynes
$C$. $PdCl_2$	$III$. Preparation of $H_2SO_4$ from $SO_2$
$D$. $Ni$ complex	$IV$. Oxidation of ethyne to ethanal

Which diagram correctly represents the change in the color of an aqueous solution of chromate ions?

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