00:03
Hi there.
00:04
In this question, we are reacting to aquaic ionic compounds.
00:07
So that means what we have here is a double replacement reaction.
00:13
You may know these as double displacement reactions as the two terms mean the same thing.
00:20
But what happens in this type of reaction is that we react to aquaicionic compounds represented here as ab and xy.
00:30
And these ions exchange places.
00:32
So the positive ion from the first combines with the negative ion.
00:35
Ion from the second, and the positive ion from the second combines with the negative ion from the first.
00:42
In order for there truly to be a reaction, one of these new products needs to be insoluble.
00:47
So we must form an insoluble product, not both of them, just one.
00:52
Typically, that means it's going to form a solid or a precipitate, but sometimes it is a liquid or a gas.
01:07
Okay, so what i want to start with here, we ultimately need the net ionic equation, but what i want to start with is just the entire equation known as the molecular equation, which i'm not sure why it's the molecular equation because these are ionic compounds, but it's always been called the molecular equation.
01:26
So i will continue with that tradition.
01:29
All right, so we are reacting manganese to nitrate, and it's of course aqueous, and our other product is sodium sulfide, also aquius.
01:47
When these exchange ions, we get the manganese 2 with its 2 positive charge, combining with the sulfide with its 2 negative charge.
01:57
Looking at the solubility rules, that's how we tell if we get an insoluble product.
02:02
We look at the solubility rules, and they tell us that most sulfides are insoluble.
02:07
The only sulfides that are soluble is when the positive ion is a group 1 metal or ammonia.
02:13
Well, manganese is not a group 1 metal.
02:16
So this is insoluble, forming our precipitate or our solid.
02:22
Our other product is going to be the sodium with its one positive charge combining with the nitrate with its one negative charge.
02:30
And we need two of those to balance...