What does ClO3- represent?

Chlorate is the correct identification of ClO3-. This anion has a chlorine atom surrounded by three oxygen atoms, and its name stems from the Latin 'chloratus,' meaning to bleach. In the context of oxoanions of chlorine, chlorate specifically refers to the presence of three oxygen atoms bonded to a central chlorine atom, distinguishing it from similar ions.

Perchlorate, which contains ClO4-, has one additional oxygen atom compared to chlorate and carries a different reactivity and stability profile. Hypochlorite, represented by ClO-, has only one oxygen atom, and is usually found in bleaching and disinfecting agents. Chlorite, indicated by ClO2-, has two oxygen atoms and is less common in comparison to chlorate.

Understanding the chemical structure and the naming conventions of these oxoanions helps clarify why ClO3- is categorized as chlorate, highlighting its unique position among chlorine-containing anions.