What compounds(or anions or cations) will make FeCl3 colourless, when it is added to the initial compound(anion or cation)?
Have you come across a strong reducing agent that reduces Fe+++ to Fe++?
In fact, Fe++ ions are generally very pale green and not completely colourless.
Sn^(2+)?
Exactly! Well done!
Thank you! I was worried about ths question stating Fe3+ becoming colourless
To make FeCl3 colorless, you need to identify compounds, anions, or cations that can react with FeCl3 to form a colorless complex. One possible way to achieve this is by adding compounds that can complex with Fe(III) ions and form stable, colorless complexes.
Here are a few examples:
1. Sodium hydroxide (NaOH): When NaOH is added to FeCl3, it reacts to form a precipitate of Fe(OH)3, which is a reddish-brown color. However, upon further addition of excess NaOH, the Fe(OH)3 will dissolve to form a colorless complex called sodium ferrate(III), NaFe(OH)4.
2. Sodium sulfide (Na2S): Adding Na2S to FeCl3 results in the formation of a black precipitate of FeS, which is insoluble. However, excess Na2S can react further to form a soluble, colorless complex called sodium ferric sulfide, Na3Fe(S2)3.
3. Potassium cyanide (KCN): When KCN is added to FeCl3, it forms a complex called potassium ferricyanide, K3Fe(CN)6, which is deep red in color. However, upon further addition of excess KCN, the colorless complex potassium ferrocyanide, K4Fe(CN)6, is formed.
These are just a few examples, and there are several other compounds that can form colorless complexes with FeCl3. It is important to note that working with certain chemicals, especially cyanide compounds, can be extremely dangerous and should only be done by trained professionals in appropriate laboratory conditions.