Citation Hunt

The Wikipedia snippet below is not backed by a reliable source. Can you find one?

Click I got this! to go to Wikipedia and fix the snippet, or Next! to see another one. Good luck!

In page Ferrous:

"

In contrast to iron(III) aquo complexes, iron(II) aquo complexes are soluble in water near neutral pH.[citation needed] Ferrous iron is, however, oxidized by the oxygen in air, converting to iron(III).[4]