An aqueous solution of metal ion M_(1) reacts separately with reagents Q and R in excess to give tetrahedral and square planar complexes, respectively. An aqueous solution of anotherr metal ion M_(2) always forms tetrahedral complex with these reagents. Aqueous solution of M_(2) on reaction with reagent S gives white precipitate which dissolves in excess of S. The reactions are summarized in the scheme given ahead. SCHEME: Tetrahedral overset(Q)underset("excess")larr M_(1)overset(R)underset("excess")rarr Square planar {:("Tetrahedral"overset(Q)underset("excess")larrM_(2)overset(R)underset("excess")rarr"Tetrahedral"),(""darrS."stoichiometric amount"),("""White ppt" overset(S)underset("excess")rarr."Precipitate dissolves"):} Reagent S is:

An aqueous solution of metal ion M_(1) reacts separately with reagents

1.	An aqueous solution of metal ion M_(1) reacts separately with reagents Q and R in excess to give tetrahedral and square planar complexes, respectively. An aqueous solution of anotherr metal ion M_(2) always forms tetrahedral complex with these reagents. Aqueous solution of M_(2) on reaction with reagent S gives white precipitate which dissolves in excess of S. The reactions are summarized in the scheme given ahead. SCHEME: Tetrahedral overset(Q)underset("excess")larr M_(1)overset(R)underset("excess")rarr Square planar {:("Tetrahedral"overset(Q)underset("excess")larrM_(2)overset(R)underset("excess")rarr"Tetrahedral"),(""darrS."stoichiometric amount"),("""White ppt" overset(S)underset("excess")rarr."Precipitate dissolves"):} Reagent S is:
Answer» `K_(4)[Fe(CN)_(6)]` `Na_(2)HPO_(4)` `K_(2)CrO_(4)` `KOH` ANSWER :D