What is the name of the polyatomic ion with the formula ClO_2^-?

• A. Perchlorate
• B. Chlorite
• C. Hypochlorite
• D. Chlorate

Answer: (B)

Verified step by step guidance

1. Identify the central atom and the number of oxygen atoms in the polyatomic ion formula \(\mathrm{ClO_2^-}\); here, chlorine (Cl) is bonded to two oxygen atoms.
2. Recall the naming pattern for chlorine oxyanions based on the number of oxygen atoms: Hypochlorite (\(\mathrm{ClO^-}\)), Chlorite (\(\mathrm{ClO_2^-}\)), Chlorate (\(\mathrm{ClO_3^-}\)), and Perchlorate (\(\mathrm{ClO_4^-}\)).
3. Match the given formula \(\mathrm{ClO_2^-}\) to the corresponding name in the series, which is Chlorite.
4. Understand that the suffix '-ite' indicates one fewer oxygen atom than the '-ate' ion, which helps distinguish Chlorite from Chlorate.
5. Confirm that the charge on the ion is negative one (\(-\)1), consistent with the typical charge for chlorine oxyanions in this series.