Which will give $Fe^{3+}$ ions in solution?

Select the correct statement$(s)$ regarding the $[Ni(DMG)_2]$ complex compound.

The number of ions present in $2.0 \ L$ of a solution of $0.8 \ M \ K_4[Fe(CN)_6]$ is

Among the statements $(a)-(d)$,the incorrect ones are:
$(a)$ Octahedral $Co(III)$ complexes with strong field ligands have very high magnetic moments.
$(b)$ When $\Delta_{0} < P$,the $d-$electron configuration of $Co(III)$ in an octahedral complex is $t_{2g}^{4} e_{g}^{2}$.
$(c)$ Wavelength of light absorbed by $[Co(en)_{3}]^{3+}$ is lower than that of $[CoF_{6}]^{3-}$.
$(d)$ If the $\Delta_{0}$ for an octahedral complex of $Co(III)$ is $18,000 \ cm^{-1}$,the $\Delta_{t}$ for its tetrahedral complex with the same ligand will be $16,000 \ cm^{-1}$.

$CuSO_{4(aq)} + 4NH_3 \rightarrow X,$ then $X$ is

The complexes given below show: