Question

Which of the following order of stability of complex ion is Incorrect?

• A. $\left[ Fe \left( C _2 O _4\right)_3\right]^{3-}<\left[ Fe \left( H _2 O \right)_6\right]^{3+}$
• B. $[ Fe ( edta )]^{-}>\left[ Fe ( en )_3\right]^{3+}$
• C. $\left[ Ni ( en )_2\right]^{2+}>\left[ Ni ( DMG )_2\right]$
• D. $\left[ Fe ( CN )_6\right]^{3-}>\left[ Fe ( CN )_6\right]^{4-}$

Answer 1

Answer: (C)

As number of stable rings increases stability of complex compound also increases due to chelation effect.
Number of rings in $\left[ Ni ( en )_2\right]^{2+}=2$
Number of rings in $\left[ Ni ( dmg )_2\right]=4$