Question

For the compound, [CoCl(NH3)5]SO4

A) provide the oxidation number for the metal in the complex ion

B) provide the coordination number of the metal in the complex ion

C) what is the charge on the complex?

D) what is the name of the coordination compound?

Answer 1

A)   [CoCl(NH3)5]SO4 ionizes as:

[CoCl(NH3)5]SO4 <====> [CoCl(NH3)5]²⁺ + SO4^2-

oxidation state of Cl = -1, NH3 = 0, charge over complex = +2. Now, suppose oxidation state of Co = X

So, X + (-1) + 0(5) = +2

X -1 = +2

X = +3 (oxidation state of Co)

B)  In the coordination sphere [CoCl(NH3)5]²⁺ there are 5 NH3 and 1 Cl

so, coordination of Co = 5 + 1 = 6

C) As compound is neutral and its counter part SO42- has -2 charge the complex must has +2 charge

D) Pentaaminechlorocobalt(III)sulphate