In general, low-spin complexes are formed by transition metals with higher oxidation states and/or ligands that create strong crystal field splitting (such as \( \text{CN}^- \)).
Based on this: - \( [\text{Fe(CN)}_5\text{NO}]^{2-} \) and \( [\text{Fe(CN)}_6]^{4-} \) are low-spin because \( \text{CN}^- \) is a strong field ligand.
- \( [\text{CoF}_6]^{3-} \) and \( [\text{Cr(H}_2\text{O})_6]^{2+} \) are high-spin due to weaker ligands or lower oxidation states.
Thus, the correct complexes that are low-spin are \( \text{Fe(CN)}_5\text{NO}^{2-} \) and \( \text{Fe(CN)}_6^{4-} \).
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 : \(A_2 \rightleftharpoons 2A\)