Question

In the complex $\left[Fe\right(H_{2}O{)}_6{]}^{3+}$, $\left[Fe\right(SCN{)}_6{]}^{3-}$,$\left[Fe\right(C_2{O}_4{)}_3{]}^{3-}$ and $[FeC{l}_6{]}^{3-}$, more stability is shown by :

• A. $\left[Fe\right(H_{2}O{)}_6{]}^{3+}$
• B. $\left[Fe\right(SCN{)}_6{]}^{-3}$
• C. $\left[Fe\right(C_2{O}_4{)}_3{]}^{3-}$
• D. $[FeC{l}_6{]}^{3-}$

Answer 1

Answer: (C)

$\left[Fe\right(C_2{O}_4{)}_3{]}^{3-}$

1) From the above information, the most stable complex is $\left[Fe\right(C_2{O}_4{)}_3{]}^{3-}$.

2) As we know that the stability of complexes increases with increase in no. of chelates present in it.

3) In the above case, $\left[Fe\right(C_2{O}_4{)}_3{]}^{3-}$ has maximum no. of chelates, therefore, it has more stability.

Therefore, the option is C.