I have a question in chemistry relating to identifying a compound that would precipitate the iron ions out of a water supply. I am unsure of a compound that would react to produce the iron as a precipitate that could be removed. Thoughts?

If you have an iron problem in your drinking water you can speak with water treatment experts. Personally, I think some of the claims are hog-wash but there are many good systems on the market. Your first job is to determine how much iron is to be removed. You asked specifically about something to ppt the iron. Aeration with air (or ozone) will oxidize the iron to the oxide and a filter can remove that; however, I don't know how effective that would be for all systems.