What is the Charge on ClO3 (Chlorate ion)? And Why?

The Charge of ClO3 (Chlorate ion) is 1-.

But the question is how can you find the charge on ClO3 (chlorate ion)?

Well there are 2 methods by which you can find the charge of ClO3.

Lets dive right into these methods one by one.

You can also refer to the below video from which you will learn to find charge of any ion.

Method 1: By looking at what it is bonded to

The charge of ClO3 (Chlorate ion) can be found out by looking at what it is bonded to.

So let’s take some examples of compounds that contain ClO₃; like Mg(ClO₃)₂, Al(ClO₃)₃, etc.

Example 1: Mg(ClO₃)₂
In Mg(ClO₃)₂, the ClO₃ is bonded to Magnesium (Mg).
You know that the ionic charge of Mg is 2+.
So you can easily say that the charge of ClO₃ should be 1-, then only it will get canceled out.
Hence the charge of ClO₃ in Mg(ClO₃)₂ is 1-.

Example 2: Al(ClO₃)₃
In Al(ClO₃)₃, the ClO₃ is bonded to Aluminum (Al).
And again, you know that the ionic charge of Al is 3+.
So here also you can easily say that the charge of ClO₃ should be 1-, then only it will get canceled out.
Hence the charge of ClO₃ in Al(ClO₃)₃ is 1-.

As seen from the above examples,
The charge of ClO3 is 1-.

In this way, you can easily find the charge of ClO3 by looking at what it is bonded to.

Method 2: By calculating the formal charge using lewis structure

In order to calculate the formal charge on ClO3 (Chlorate ion), you should know the Lewis dot structure of ClO3 (Chlorate ion).

Here is the lewis structure of ClO3.

Now using the above lewis structure of ClO3, you have to find the formal charge on each atom that is present in the ClO3 molecule.

For calculating the formal charge, you need to remember this formula;

Formal charge = Valence electrons – Nonbonding electrons – (Bonding electrons)/2

You can see the bonding and nonbonding electrons of ClO3 from the image given below.

So now let’s calculate the formal charge on each individual atom present in ClO3.

Formal charge on Chlorine atom:
Valence electrons = 7 (as it is in group 17 on periodic table) ^[1]
Nonbonding electrons = 2
Bonding electrons = 10

So according to the formula of formal charge, you will get;

Formal charge on Chlorine = Valence electrons – Nonbonding electrons – (Bonding electrons)/2 = 7 – 2 – (10/2) = 0

So the formal charge on chlorine atom is 0.

Formal charge on double bonded Oxygen atom:
Valence electron = 6 (as it is in group 16 on periodic table) ^[2]
Nonbonding electrons = 4
Bonding electrons = 4

So according to the formula of formal charge, you will get;

Formal charge on double bonded Oxygen = Valence electrons – Nonbonding electrons – (Bonding electrons)/2 = 6 – 4 – (4/2) = 0

So the formal charge on double bonded oxygen atom is 0.

Formal charge on single bonded Oxygen atom:
Valence electron = 6 (as it is in group 16 on periodic table)
Nonbonding electrons = 6
Bonding electrons = 2

So according to the formula of formal charge, you will get;

Formal charge on single bonded Oxygen = Valence electrons – Nonbonding electrons – (Bonding electrons)/2 = 6 – 6 – (2/2) = 1-

So the formal charge on single bonded oxygen atom is 1-.

Now let’s put all these charges on the lewis dot structure of ClO3.

So there is overall 1- charge left on the entire molecule.

This indicates that the ClO3 (Chlorate ion) has 1- charge.

I hope you have understood the above calculations of ClO3 (Chlorate ion). But for your tests, you don’t need to remember the entire calculations. You should just try to remember that ClO3 has 1- charge.

Check out some other related topics for your practice.

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Charge of Cadmium (Cd)
Charge of Titanium (Ti)
Charge of Gallium (Ga)
Charge of Silicon (Si)
Charge on HCl (Hydrochloric acid)