Howdy Yall! Mr. Causey coming to you from beautiful
Atascocita, Texas and today we're going to look at
net ionic equations.
In this lesson we're going to talk about total ionic equations, we're going to take a look at
spectator ions
and write a net ionic equation.
You must know the periodic table,
oxidation numbers, how to write equations,
how to balance equations, and your solubility rules
and if you don't know any of these be sure to go to my
YouTube channel and check out the lessons
that you aren't totally up on yet. And you will need
a periodic table, you will need a polyatomic ion chart and if you don't have one of these go
to this link
right here and pick up your free polyatomic ion chart.
On the back, it has a lot of other great stuff such as your solubility rules
and your reactivity scale. Alright, the basic steps.
One, write a balanced equation.
Two, write a total ionic equation. Then, remove the spectator ions
and rewrite the equation and that will be your
net ionic equation. So what is a total ionic equation?
It is a chemical equation that shows all the ions
in a reaction such as taking this reaction right here which is just a
common neutralization reaction.
We know that sodium hydroxide and hydrochloric acid will
dissociate
and ionize.
What are spectator ions? The ions in a chemical reaction that are unchanged.
So if we go back and look at our total ionic equation,
note that Sodium and Chlorine are unchanged;
therefore, they are spectator ions.
And then we write a net ionic equation
which is a chemical question that shows only those ions
that change but it ignores those that don't change or the spectator ions as they're called.
So here's our reaction again,
we know sodium is a spectator ion
and we know that chlorine is a spectator ion so we cancel those out
and rewrite the equation. There's our net ionic equation.
So, let's look at an example. A bar of zinc metal is immersed in a solution of copper(II) sulfate.
The first thing I want to do is go to my reactivity table
and make sure that zinc will be more reactive than copper
and it is, so they are going to change places.
Zinc is greater than copper.
So let's go to the board and write that equation out.
So we have zinc solid and copper(II) sulfate aqueous
and that's going to give us zinc sulfate,
an aqueous solution, and copper solid. And that's already balanced
and it's a single replacement reaction. Now, copper (II) sulfate
and zinc sulfate are both soluble and I'm just going to check my solubility
rules and yes note that
all sulfates are soluble except for a few and both Copper sulfate and Zinc sulfate
are soluble.
So they will dissociate and we will get
copper and sulfate ions and we will get zinc
and Sulfate ions. So let's rewrite that now.
Here's our whole, total ionic equation
and note that we have spectator ions.
Sulfate is going to be cancelled out
and then we can rewrite that
and there's out net ionic equation. Alright, if you're
not sure what happened, be sure to go back and rewatch this
and then practice some equations of
your own. Let's review. You wrote a balanced equation,
then you wrote a total ionic equation, removed the spectator ions,
and you got a net ionic equation. If you have any questions, send an email to
mrcausey@mrcausey.com and don't forget to check out mrcausey.com for more
videos and
handouts, it's growing every day, and subscribe to my YouTube channel.