question_answer

Direction: The dissociation of complex may be expressed as \[{{[M{{L}_{x}}]}^{4+}}\,+xL\] and equilibrium constant of this is known as instability constant which is a measure of stability. The stability of complex depends on EAN of central atom, charge on metalion, basic nature of ligand and chelation.

Which complex is most stable where \[{{K}_{d}}\] is un stability constant?

A)  \[{{[Cu\,{{(CN)}_{2}}]}^{-}}\,{{K}_{d}}=1\times {{10}^{-16}}\]

B)  \[{{[Fe{{(CN)}_{6}}]}^{4-}}{{K}_{d}}=1\times {{10}^{-37}}\]

C)  \[{{[Fe{{(CN)}_{6}}]}^{3-}}{{K}_{d}}=1\times {{10}^{-44}}\]

D)  \[[Ag{{(CN)}_{2}}^{-}{{K}_{d}}=1\times {{10}^{-20}}\]