The crystal field stabilization energy (CFSE) depends on the oxidation state and the ligand field strength.
Generally:
- The higher the oxidation state of the metal, the stronger the ligand field and the higher the CFSE.
- \( \text{NH}_3 \) is a stronger field ligand than \( \text{en} \) (ethylenediamine).
Thus: - \( [\text{Co(NH}_3)_4]^{2+} \) will have the lowest CFSE, as it is in a lower oxidation state.
- \( [\text{Co(NH}_3)_6]^{2+} \) has a higher CFSE compared to \( [\text{Co(NH}_3)_4]^{2+} \).
- \( [\text{Co(NH}_3)_6]^{3+} \) has a higher oxidation state, leading to higher CFSE.
- \( [\text{Co(en)}_3]^{3+} \) has the highest CFSE due to the strong ligand field of \( \text{en} \).
Hence, the correct order is:
\[[\text{Co(NH}_3)_4]^{2+} < [\text{Co(NH}_3)_6]^{2+}<[\text{Co(NH}_3)_6]^{3+} < [\text{Co(en)}_3]^{3+}\]What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)

Cobalt chloride when dissolved in water forms pink colored complex $X$ which has octahedral geometry. This solution on treating with cone $HCl$ forms deep blue complex, $\underline{Y}$ which has a $\underline{Z}$ geometry $X, Y$ and $Z$, respectively, are

What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)