The problem involves understanding the magnetic properties of coordination complexes. Let's analyze both the complexes given in the question.
Thus, the correct answer is that \([\text{Ni(CO)}_4]\) is diamagnetic, and \([\text{NiCl}_4]^{2-}\) is paramagnetic.
To determine the magnetic properties of the complexes \(\text{[Ni(CO)}_4\text{]}\) and \(\text{[NiCl}_4\text{]}^{2-}\), we need to consider the following:
The correct property for the given options is:
Therefore, the correct option is: \( \text{[Ni(CO)}_4\text{]} \) diamagnetic, \( \text{[NiCl}_4\text{]}^{2-} \) paramagnetic.
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 : \(A_2 \rightleftharpoons 2A\)