What is the Charge on NH4 (Ammonium ion)? And Why?

The Charge of NH4 (Ammonium ion) is 1+.

But the question is how can you find the charge on NH4 (ammonium ion)?

Well there are 2 methods by which you can find the charge of NH4.

Lets dive right into these methods one by one.

If you are a visual learner like me, then here is a short two minute video for you.

Method 1: By looking at what it is bonded to

The charge of NH4 (Ammonium ion) can be found out by looking at what it is bonded to.

So let’s take some examples of compounds that contain NH₄; like NH₄Cl, (NH₄)₂O, etc.

Example 1: NH₄Cl
In NH₄Cl, the NH₄ is bonded to Chlorine (Cl).
You know that the ionic charge of Cl is 1-.
So you can easily say that the charge of NH₄ should be 1+, then only it will get canceled out.
Hence the charge of NH₄ in NH₄Cl is 1+.

Example 2: (NH₄)₂O
In (NH₄)₂O, the NH₄ is bonded to Oxygen (O).
And again, you know that the ionic charge of O is 2-.
So here also you can easily say that the charge of NH₄ should be 1+, then only it will get canceled out.
Hence the charge of NH₄ in (NH₄)₂O is 1+.

As seen from the above examples,
The charge of NH4 is 1+.

In this way, you can easily find the charge of NH4 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 NH4 (Ammonium ion), you should know the Lewis dot structure of NH4 (Ammonium ion).

Here is the lewis structure of NH4.

Now using the above lewis structure of NH4, you have to find the formal charge on each atom that is present in the NH4 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 NH4 from the image given below.

So now let’s calculate the formal charge on each individual atom present in NH4.

Formal charge on Nitrogen atom:
Valence electrons = 5 (as it is in group 15 on periodic table) ^[1]
Nonbonding electrons = 0
Bonding electrons = 8

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

Formal charge on Nitrogen = Valence electrons – Nonbonding electrons – (Bonding electrons)/2 = 5 – 0 – (8/2) = 1+

So the formal charge on nitrogen atom is 1+.

Formal charge on Hydrogen atom:
Valence electron = 1 (as it is in group 1 on periodic table) ^[2]
Nonbonding electrons = 0
Bonding electrons = 2

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

Formal charge on Hydrogen = Valence electrons – Nonbonding electrons – (Bonding electrons)/2 = 1 – 0 – (2/2) = 0

So the formal charge on hydrogen atom is 0.

Now let’s put all these charges on the lewis dot structure of NH4.

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

This indicates that the NH4 (Ammonium ion) has 1+ charge.

I hope you have understood the above calculations of NH4 (Ammonium ion). But for your tests, you don’t need to remember the entire calculations. You should just try to remember that NH4 has 1+ charge.

Check out some other related topics for your practice.

Related topics:
Charge of Copper (Cu)
Charge of Nitrogen (N)
Charge on Ammonia (NH3)
Charge of Bromine (Br)
Charge of OH (Hydroxide ion)