2007-07-25 03:37:31 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
In aqueous solution chromate and dichromate anoins are in a chemical equilibrium :
2 CrO42- + 2 H3O+ <----> Cr2O72- + 3 H2O
This equilibrium can be pushed towards dichromate by lowering the pH or in the other direction towards chromate by raising the pH to basic.
Adding Cu(NO3)2 that is a srong electrolyte >>
Cu2+ + 2NO3-
Cu2+ + CrO42- >> CuCrO4 that will precipitate since it is a slightly soluble salt
CuCrO4 <------> Cu 2+ + CrO42-
Ksp = 3.6 x 10^-6
2007-07-25 05:07:27 · answer #1 · answered by Dr.A 7 · 0⤊ 0⤋
By precipitating CrO4(2-) with an ion like Ba2+.
2007-07-25 05:03:54 · answer #2 · answered by ag_iitkgp 7 · 0⤊ 0⤋
If you add some silver nitrate the you will precipitate silver chromate if the ion is present
2007-07-25 10:08:15 · answer #3 · answered by scott k 4 · 0⤊ 0⤋