The number of ions present in $2 \ L$ of a solution of $1.6 \ M \ K_4[Fe(CN)_6]$ is:

Which of the following statements is correct?

Total number of molecules/species from the following which will be paramagnetic is $........$
$O_2, O_2^{+}, O_2^{-}, NO, NO_2, CO, K_2[NiCl_4], [Co(NH_3)_6]Cl_3, K_2[Ni(CN)_4]$

Which of the following has a yellow colour?

In which of the following complexes is the pairing of $(n-1)d$ electrons $NOT$ present in the presence of strong field ligands $(SFL)$?

Given below are two statements.
Statement $I$: In $CuSO_{4} \cdot 5H_{2}O$,$Cu-O$ bonds are present.
Statement $II$: In $CuSO_{4} \cdot 5H_{2}O$,ligands coordinating with $Cu(II)$ ion are $O$- and $S$-based ligands.
In the light of the above statements,choose the correct answer from the options given below.