What is the formula for hexafluorocobaltate(III)? Is it high spin or low spin?
1 Answer
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 (
Since the overall charge is negative, and
#["CoF"_6]^(3-)# where the oxidation state of cobalt here must be
#color(blue)(+3)# , since...
#overbrace((+3))^(Co) + overbrace(6(-1))^(6xxF^(-)) = overbrace(-3)^("overall")# #color(blue)(sqrt"")#
Thus, with
-
Is this compound colored? Would you expect any charge-transfer bands in the UV-VIS spectrum?
(There should be ligand-to-metal charge transfer, LMCT.) -
Is there Jahn-Teller distortion in this complex? Is it weak or strong?
(should be weak) -
Is this compound paramagnetic, i.e. does it have any unpaired electrons?
(yes. Should be 4.) -
What is the spin-only magnetic moment?
(#mu_S = 2.0023sqrt(S(S+1))# , where#S# is the total electron spin.)
These are all questions that are totally valid on third-year or fourth-year undergraduate exams. The first and third bullet point questions, probably first or second year.