What is FeC13?

Answer 1

Do you mean FeCl3? (l = lower-case L?) That would be iron chloride.

Answer 2

FeCl3 is the chemical formula for iron(III) chloride, which is a compound composed of iron and chlorine ions. It is commonly used as a catalyst in organic synthesis reactions and as a coagulant in water treatment processes. It is a yellow-brown solid at room temperature.