What is the Difference Between Chlorate and Perchlorate?

Chlorate and perchlorate are both oxyanions of chlorine, but they have different structures and stabilities. Here are the key differences between them:

1. Stability: Chlorate is a salt of chloric acid, while perchlorate is obtained from perchloric acid. Chlorate is less stable than perchlorate due to its lower oxidation state and fewer resonance structures. However, perchlorate has a higher oxidation state and a greater number of resonance structures, which contribute to its greater stability.
2. Oxidation State: Chlorate has an oxidation state of +5, while perchlorate has an oxidation state of +7. Despite the higher oxidation state in perchlorate, its tetrahedral structure and high symmetry of the central ion provide greater stability.
3. Formation: Chlorate is formed as a by-product when using chlorine, chlorine dioxide, or hypochlorite for the disinfection of drinking water, water for food production, and surfaces coming into contact with food. On the other hand, perchlorate is a contaminant that can be naturally present in the environment or result from human activity, such as the use of fertilizers and irrigation water contaminated with perchlorate.

In summary, chlorate and perchlorate are both oxyanions of chlorine, but they differ in their stability, oxidation state, and formation processes. Chlorate is less stable than perchlorate due to its lower oxidation state and fewer resonance structures, while perchlorate has a higher oxidation state and greater stability due to its tetrahedral structure and high symmetry of the central ion.

Comparative Table: Chlorate vs Perchlorate

The main difference between chlorate and perchlorate ions is the number of oxygens in their respective structures. Here is a comparison table highlighting the differences between chlorate and perchlorate:

Both chlorate and perchlorate are oxyanions of chlorine, but perchlorate has one more oxygen atom than chlorate. Chlorate and perchlorate compounds are strong oxidizers, and they should be kept away from easily oxidized materials. The stability of perchlorate compared to chlorate is due to differences in the distribution of charge and molecular structure.