In $K_4[Fe(CN)_6]$,the primary valency of iron is .........

Explain the terms 'Coordination Entity' and 'Central Atom/Ion' in the context of coordination compounds.

According to Werner's theory,the primary valency of a central metal ion is:

On treating $100 \ mL$ of $0.1 \ M$ aqueous solution of the complex $CrCl_3 \cdot 6 H_2 O$ with excess of $AgNO_3$,$2.86 \ g$ of $AgCl$ was obtained. The complex is:

The coordination number of cobalt in the coordination compound $[Co(en)_2Br_2]Cl_2$ is ........ .

Identify the anionic complex from the following.