Sciencemadness Discussion Board

reaction problem

coolrunnings - 25-10-2005 at 00:14

I reacted CuSO4 with KI in solution
As expected a precipitate was formed, however, CuI is suppost to be a grey precipitate while i got a red precipitate.

I'm guessing there was some sort of ligand formed.

Can anyone please help me with a definitive answer?

Mephisto - 25-10-2005 at 02:29

Usually the precipitate has a brown colour because of the precipitating iodine. The unstable CuI2 is formed intermediately, which decomposes to CuI and I2.

~Mephisto

coolrunnings - 25-10-2005 at 02:30

thank you very much
i discovered then answer soon after i asked this question.
sorry this was an easy question i had a mental blank or something.

[Edited on 25-10-2005 by coolrunnings]