I am writing a report for an experiment for the preparation of potassium tetracyanonickelate(II) hydrate.
the procedure started by:
dissolving 8g of nickel(II) sulfate in 25ml of water. Then 4g of KCN in 10ml of water were added. Now this gave a sky blue precipitate. I didn't find any information about this 'intermediate'.
Then, 4g of KCN in 8ml water were added to this precipitate, and the final required product was obtained. It is yellow coloured, and known to have a square planar structure.
Does anyone have any idea what the sky blue precipitate may be? My first thought was that it may be the octahedral form of the product, IE hexacyanonickelate(II) but apparently it doesn't even exist.