Question

Wolte the formula of the complex sodium hexa flouridocobaltate 3

​

Answer 1

Notice the "-ate" at the end. That indicates a negative overall charge to the complex. From there, we can deduce the oxidation state of cobalt.

"Hexafluoro" indicates six fluoro (

F

−

) ligands, and the

III

indicates the oxidation state of cobalt has a magnitude of

3

.

Since the overall charge is negative, and

9

−

would be an absurd charge, we therefore have, for hexafluorocobaltate(III):

[

CoF

6

]

3

−