00:01
This question addresses ionic equations.
00:04
They're asking us to write based on what we're given complete and net ionic equations for each example.
00:12
So for the first example, we were given that we have potassium sulfate reacting with calcium iodine to produce a solid calcium sulfate and aqueous potassium iodine.
00:23
So the little aqueous subscript always represents the fact that that means we have ions independently floating around in solution.
00:32
So if we were to rewrite sort of what's going on, in terms of the potassium sulfate, we really do have free potassium ions floating around and free sulfate ions floating around that are available to react with something else.
00:48
The same case is true here of the calcium iodide.
00:51
We have calcium ions and iodide ions that are floating around in solution.
00:59
And in terms of our products, we have potassium and iodide ions that ultimately are going to be formed as part of the product or be left as part of the product.
01:13
So only in the case of this calcium sulfate solid, do we not have free ions that are capable of reacting with something.
01:22
In fact, we have combined those free calcium ions with the sulfate ions, and they are no longer sort of free to run.
01:29
They now become part of the solid material and are essentially tied up.
01:36
The only free ions that are still left are those potassium and iodide ions.
01:43
And these are what we refer to as spectator ions.
01:47
So spectator ions do not combine to form a solid.
01:52
They really aren't part of the reaction.
01:54
They're just present as kind of like spectators in an audience that are just there to kind of help drive the reaction or the process.
02:03
So in a net reaction, we don't show the spectator ions.
02:10
So the net reaction, this would be the complete reaction, completely balanced, showing every species involved, even the spectator ions, and the net reaction or process, we would show only the ions that interact.
02:25
So that would be the calcium and the sulfate.
02:32
And we would show the formation then of calcium sulfate solid is our net reaction and leave out the spectator ions in this example.
02:46
The next example, we're going to write this, a little distinguish it a little differently than they did at the beginning by showing each of the independent ions that's involved here.
02:56
So instead of saying ammonium chloride, we divided it into the ammonium and chlorine ions.
03:02
And instead of saying sodium hydroxide, we divided it into sodium and hydroxide ions because we know that's how these ions independently exist in solution.
03:12
So what ends up happening is water as a liquid and ammonia gas are formed...