Identify the number of donor groups present in $EDTA$.

Give the chemical formulas for the following:
$(i)$ Sodium nitroprusside
$(ii)$ The purple solution formed in the test for sulphur
$(iii)$ Sodium hexacyanoferrate $(II)$
$(iv)$ Iron $(III)$ hexacyanoferrate $(II)$
$(v)$ Ferri-ferrocyanide
$(vi)$ Sodium thiocyanate

The formula of the complex hydridotrimethoxyborate$(III)$ ion is:

What is the secondary valence of $Co^{3+}$ ion according to Werner's theory in $[Co(NH_3)_4 Cl_2]^+$?

What is the coordination number of $Pt$ in cisplatin?

Identify the tetradentate ligand from the following.