Chlorate Formula

Chlorate (ClO3 name) is an inorganic anionic compound that is monovalent in nature and is synthesized by the deprotonation of chloric acid. Thus it is also known as chlorine oxoanion and is a conjugate base of chloric acid. Thus the chlorate formula of chlorate anion is ClO3-. Chlorine has an oxidation state of +5 and thus the chlorate can be referred to as the compounds that incorporate this anion. Chlorate is a white crystalline inorganic solid which is a strong oxidizing agent and thus should be kept away from any organic or easily oxidized compounds. It itself is non - combustible in nature but can form a very aggressive flammable mixture with combustible compounds and it usually takes the shape of an explosive if it is mixed with very finely grounded combustible material.

This type of combustion takes place by friction. For instance chlorate in contact with sulfonic acid causes explosion or when mixed with an ammonium salt, spontaneous decomposition and ignition take place. Thus it is a readily deflagrate compound. Chlorate for its highly inflammable property was widely used as protecniques but its application reduced over the years because of its high instability and perchlorate is used as one of the stable alternatives to it. 

Chlorate Structural Formula

As per valence shell electron pair repulsion theory, it is a triangular bipyramidal structure dispide its sp3 hybridization that calls for a tetrahedral structure and that is because of the lone pair of electrons present with the central atom chlorine.  The bond order of the chlorate ion is 1.6 and the bond angle between central atom Cl and O is 1.57 (M-O) and has 2 such bonds with two atoms of oxygen and one double bond with oxygen with a lone pair of electrons. 

Now as the bond order increases the bond length decreases, thus the bond length of chlorate ion (ClO3-) is more than ClO4- but less than ClO2-. The chlorate ion (ClO3-) has a bond angle of 109o due to the presence of one lone pair of electrons and three bonded pairs of electrons. Thus it is difficult to explain the chlorate formula by one single lewis structure for all the chlorate compounds as chlorate ion is hypervalent in nature and it forms a hybrid of multiple resonance structures. Thus the resonance structure of chlorate ions is as illustrated below.

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In order to understand the chlorate formula or the chlorate chemical formula, the three following concepts need to be elaborated to understand its structural orientation.

1. Lewis Structure: by analyzing the chlorate ion, it is clear that three oxygen atoms are attached to one chlorine atom with a -1 charge over the whole ion. Chlorine is situated in the 7th group and oxygen is a 6th group element according to the modern periodic table. Thus oxygen can have a maximum of 6 valence electrons in its outermost shell whereas chlorine can have a maximum of 7 valence electrons in its outermost shell. Thus the total number of valence electrons given by one chlorine atom is 7 x 1 = 7

As there are three atoms of oxygen in chlorate ion [ClO3-], therefore total valence electrons of oxygen atoms are 6 x 3 = 18. And as there is one negative charge on the atom, thus the received electron to valence electron is 1. Thus total valence electron of chlorate ion = 7 + 16 + 1 = 26.  

Thus the total number of paired electrons will be the summation of the 𝛔 + 𝝅 + lone pair of electrons which is equal to 26 / 2 = 13 pairs of electrons. The central atom always has the greater ability to accommodate more valence electrons and in this case, it is the chlorine atom due to the presence of d-orbital to accommodate the valence electrons. Therefore the initial structure of chlorate ion [ClO3-] is as follows:

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As there is already three sigmas (𝛔) bonds of oxygen atoms established with the chlorine atom thus there are ten remaining lone pairs in the atom that are needed to be marked as lone pairs available to make bonds on the three oxygen atoms. Thus one oxygen atom will take a maximum of three lone pairs of electrons according to the octane rule. There is only one lone pair of electrons left that is marked on the central atom [Cl ].

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Since in the above structure, all the atoms possess high charges on them, thus the structure is very unstable in nature. Thus in order to make the structure stable one lone pair of each of the two oxygen atoms will be sharing it with the chlorine atom making two pi (𝝅) bonds and hence chlorine atom now has 12 electrons around chlorine atoms and due to the vacant d-orbital of a chlorine atom, it can hold 10 electrons in pair. Thus a lone pair will be left out on chlorine atoms. Also, there are no charges left on the two oxygen atoms. Thus the final structure formed of chlorate ions is much more energy stable in nature. Thus the final Lewis structure will be as follows.

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2. Hybridization: hybridization is commonly used to describe the nature of the covalent bonds formed between different atoms. Thus hybridization can be defined as a process of mixing of different valence shells of the same atom but possessing different energies so that the redistribution that is taking place between these orbitals or the electrons present in these orbitals can lead to the same energy levels and identical shapes for various molecules undergoing hybridization. Thus these orbits post hybridizations are called hybrid orbits. The basic equation used to identify the hybridization of various atoms present in a molecule sharing covalent bonding is

X = ½ [ { no. of valence electrons of central atom} +{ no. of monovalent atoms} + { charge of anions} - { charge of cations} ].                    

X = ½ [ VE + MA + a - c ]

Thus, in the case of chlorate ion  [ClO3-], the chlorine being the central atom has seven valence electrons, no cation charges, only one anionic charge and oxygen is divalent in nature, so no monovalent atoms either. Thus putting all the numbers in the equation 

X = ½ [ 7+0 + 1- 0] = 4. Therefore, the hybridization is sp3 hybridization that points to

Tetrahedral structure but due to the lone pair of electrons, it has a pyramidal structure. 

The illustration for hybridization will provide a clearer picture of the hybridization of the chlorate ion taking place.

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3. VSEPR Theory: Lewis theory is only helpful to find out the two-dimensional molecular structure of the compound or an ion but in order to understand the three dimensional as well as planer configuration of the molecule VSEPR theory is important. It also helps in understanding the bond length and bond angle of the atoms with the central atom in a particular hybridization. As chlorate ion has one lone pair with three bonded atoms thus it possesses AX3E generic formula that shows it is trigonal pyramidal with 109 bond angle. Thus the following table is given below for a clear understanding. 

Here A is the central atom, X is bonded atoms to central electron and E is the lone pairs of  Electrons.

Preparation

In the laboratory, chlorate ions are prepared by adding chlorine to the metal oxides after heating them at high temperature. Some of such metal oxides are KOH. thus the chemical formula of chlorate in laboratory preparation is as follows

3Cl2 + 6 KOH → 5 KCL + KClO3 + 3 H2O

Chlorites are relatively toxic in nature but they become neutral once they undergo the reduction process and become harmless.

Other Oxyanions of Chlorate