Give the chemical formula for (a) chlorite ion, (b) chloride ion, (c) chlorate ion, (d) perchlorate ion, (e) hypochlorite ion.
The Correct Answer and Explanation is:
Answers:
(a) Chlorite ion: ClO₂⁻
(b) Chloride ion: Cl⁻
(c) Chlorate ion: ClO₃⁻
(d) Perchlorate ion: ClO₄⁻
(e) Hypochlorite ion: ClO⁻
Explanation:
Chlorine can form several oxyanions depending on the number of oxygen atoms bonded to it. The naming of these ions follows a specific pattern based on the oxidation state of chlorine and the number of oxygen atoms present. The suffixes and prefixes used in their names help to distinguish between the different ions.
The chloride ion (Cl⁻) is the simplest form, containing only the chlorine atom with a single negative charge and no oxygen atoms. It forms when chlorine gains one electron.
The hypochlorite ion (ClO⁻) contains one oxygen atom. The prefix “hypo-” means “less than”, and the suffix “-ite” is used for the ion with fewer oxygen atoms compared to others in the series.
The chlorite ion (ClO₂⁻) includes two oxygen atoms. It carries the “-ite” suffix, which indicates an oxyanion with fewer oxygen atoms than its “-ate” counterpart.
The chlorate ion (ClO₃⁻) has three oxygen atoms. The “-ate” suffix indicates an oxyanion with more oxygen atoms compared to the “-ite” ion.
The perchlorate ion (ClO₄⁻) contains four oxygen atoms. The prefix “per-” means “more than”, and it is used with the “-ate” suffix to indicate the oxyanion with the highest number of oxygen atoms in the chlorine series.
These ions are part of a common group of halogen oxyanions, and their systematic naming provides a way to predict the chemical composition based on the name alone. Understanding the pattern helps in writing correct formulas and recognizing the oxidation states of chlorine in different compounds.
