IPA: //ˈkroʊməs//
KK: /ˈkroʊməs/
Relating to or containing chromium, particularly in a form where it has a valence of two.
The chromous compound was used in the chemical reaction.
Chromous → It is formed from "chroma" (from Greek χρῶμα, meaning color) and "-ous" (meaning possessing or full of). The word "chromous" refers to a state of possessing color, specifically relating to certain compounds of chromium that exhibit a specific color.
Think of 'chroma' meaning color, and remember that 'chromous' refers to something that possesses a specific color.