Difference Between Chlorate and Perchlorate

The key difference between chlorate and perchlorate is that chlorate is the anion derived from the dissociation of chloric acid whereas perchlorate is the anion derived from the dissociation of perchloric acid.

Chlorate and perchlorate are oxyanions containing chlorine and oxygen atoms. In general, these terms are used also to name the salts of chloric and perchloric acid respectively. In other words, the term chlorate may refer to any compound containing chlorate anion with another cation.

1. Overview and Key Difference
2. What is Chlorate
3. What is Perchlorate
4. Side by Side Comparison – Chlorate vs Perchlorate in Tabular Form
5. Summary

What is Chlorate?

Chlorate is an anion having the chemical formula ClO₃^–. The oxidation state of chorine atom is +5. However, the chemical compounds containing this anion are also named as chlorates as a general term. This anion is the salt of choric acid. The structure of this anion is as follows:

The geometry of this anion is trigonal pyramidal. Moreover, the compounds containing this anion are strong oxidizers. Therefore, we have to keep them away from easily oxidized materials. This anion can show resonance; therefore the actual structure of chlorate is a hybrid structure, which has all Cl-O bond with the same length. Moreover, the chlorine atom here is hypervalent. This means the chlorine atom has more than eight electrons around it.

When considering the preparation, in the laboratory, we can produce chlorates by adding chlorine to hot hydroxides, i.e. KOH. In the industrial scale, we can produce it from the electrolysis of aqueous sodium chloride.

What is Perchlorate?

Perchlorate is an anion having the chemical formula ClO₄^–. It originates from perchloric acid. In general, this term may refer to any compound containing perchlorate anion. The oxidation state of chorine atom in this compound is +7. It is the least reactive form among other chlorates. The geometry of this ion is tetrahedral.

Mostly, compounds containing this anion exists as colourless solids that are soluble in water. This anion forms when perchlorate compounds dissociate in water. In the industrial scale, we can produce this ion via electrolysis method; here, oxidation of aqueous sodium chlorate occurs.

What is the Difference Between Chlorate and Perchlorate?

The key difference between chlorate and perchlorate is that chlorate is the anion derived from the dissociation of chloric acid whereas perchlorate is the anion derived from the dissociation of perchloric acid. Furthermore, the oxidation state of chlorine atom in chlorate is +5 and the oxidation state of perchlorate is +7. When considering the geometry of these anions, chlorate anion has trigonal pyramidal geometry and perchlorate anion has tetrahedral geometry.

Summary – Chlorate vs Perchlorate

Chlorate and perchlorate are basically oxyanions of chorine. The key difference between chlorate and perchlorate is that chlorate is the anion derived from the dissociation of chloric acid whereas perchlorate is the anion derived from the dissociation of perchloric acid.

Reference:

1. “Chlorate.” Wikipedia, Wikimedia Foundation, 27 Aug. 2019, Available here.

Image Courtesy:

1. “Chlorate-2D” By Benjah-bmm27 – Own work (Public Domain) via Commons Wikimedia
2. “Perchlorate-2D-dimensions” By By Benjah-bmm27 – Own work (Public Domain) via Commons Wikimedia