Question

Consider the coordination compound, [CoCl(NH_3)_4(H_2O)]SO_4. Use the definitions in the Introduction to identify the following with the formula and charge (if applicable). a. the ligand(s) b. the complex. c. the coordination sphere d. the coordination number of cobalt Write the formula of the complex ion that forms between a. the ligand Cl^- and the platinum(II) ion with a coordination number of four. b. the ligand ethylenediamine (abbreviated "en", and the chromium(III) ion with a coordination number of six. c. the ligand dihydrogen ethylenediaminetetraacetate, (abbreviated H_2Y^2-), and the zinc(II) ion with a coordination number of four. See Table 36.1. Experimental Procedure, Parts A-D. Identify the chemicals that are cited as cautions.

Answer 1

Ans 1.

a) ligand : ligand is the ion or molecule that is bound to the central metal atom or ion.

Here the ligands are Cl, NH₃ and H₂O

b) The complex : complex atom or ion in the coordination entity is the one to which fixed number of ions or groups are attached.

Here the complex is Cobalt (Co)

c) Coordination sphere : It constitutes the central metal atom / ion along with its attached ligands

Here the coordination sphere is , [CoCl(NH₃)₄(H₂O)]

d) The coordination number of central metal is defined as the number of ligands it is directly bonded to.

Here cobalt is bonded to one chloride ion , four ammonia molecules and one water molecule.

So the coordination number of cobalt is 6