Can you make a Lewis structure of dichromate ion, i.e. #Cr_2O_7^(2-)#?

1 Answer
Apr 27, 2017

#"In dichromate..........?"#

For #(""^(-)O-)(O=)_2Cr-O-Cr(=O)_2(-O^(-))#

Explanation:

Well, let's count them up.

Well each chromium centre is tetrahedral to a first approx., so there are #2xx6#, and one #/_Cr-O-Cr#, so this gives 13 in total. Make a model, and see if you agree with me. (I did not make a model because I am lazy!). I have treated all #/_O-Cr-O# and #/_Cr-O-Cr# as tetrahedral to a first approx.