[Cr (en)2 (H2O) Cl] SO4 .What is its name?

1 Answer
Oct 26, 2017

#"aquachlorobis(ethylenediamine)chromium(III) sulfate"#

What is the electron geometry of this complex?


You should have memorized the following ligands:

  • #"en"# = ethylenediamine, charge = #0#
  • #"H"_2"O"# = aqua, charge = #0#
  • #"Cl"^(-)# = chloro, charge = #-1#

(Remember that #"ammine"# is for the #"NH"_3# ligand, with two #"m"#'s.)

Then you list them alphabetically in front of the metal, along with its oxidation state and the anion. Complicated ligand names use the following prefixes (use your best judgment...):

  • #2 = "bis"#
  • #3 = "tris"#
  • #4 = "tetrakis"#
  • #5 = "pentakis"#
  • #5 = "hexakis"#

Sulfate is #"SO"_4^(2-)#, so the cation is #+2#:

#["Cr"("en")_2("H"_2"O")"Cl"]^(2+) + "SO"_4^(2-)#

That implies that chromium is #+3# since #"en"# is neutral and #"H"_2"O"# is neutral but #"Cl"^(-)# is #-1#.

Thus, we get:

#color(blue)"aquachlorobis(ethylenediamine)chromium(III) sulfate"#