Answer
a) Ethylenediamine
b) 3+
c) 4
d) en
Work Step by Step
a) en abbreviates ethylenediamine
b) The only ligand with a charge is CN with a 1- charge. Since the compound has a total charge of 3+, Cobalt must have a 3+ charge
c) There are four ligands in this coordination compound so the coordination number is four
d) Ethylenediamine is a bidentate