How can you tell if there is iron in a compound?

Answer 1

you can take a magnet if you see little iron filling it contains iron

Answer 2

One way to determine if iron is present in a compound is through chemical tests such as the Prussian blue test, which forms a blue color in the presence of iron. Another method is using spectroscopic techniques like UV-Vis or X-ray fluorescence to detect the characteristic absorption/emission lines of iron atoms in the compound. Analysis using techniques such as atomic absorption spectroscopy or inductively coupled plasma mass spectrometry can also provide quantitative information about the iron content in a compound.