00:02
There, in this question we have a metathesis reaction, which is also known as a double replacement reaction.
00:16
And a double replacement is also known as a double displacement.
00:20
But all of these mean the same type of reaction.
00:24
Metathesis is typically a little bit of an older name that isn't used as much today, but it still means the same type of reaction.
00:32
In this type of reaction, we have two aqueous ionic compounds, which i'm representing here as ab and xy.
00:40
And what they do is they exchange ions.
00:41
The positive ion from the first combines with the negative ion from the second, and the positive ion from the second combines with the negative ion from the first.
00:50
By definition, we only have a product, we only have a reaction if an insoluble product is formed.
00:56
Okay, so let's look at this reaction.
00:58
We have agno3, silver nitrate, which is aqueous.
01:05
It is reacting with sodium sulfide, na2s, also aqueous.
01:15
All right, so we want to know the products that will form.
01:18
They're going to exchange ions.
01:20
So the positive ion from the first, the silver, combines with the sulfide.
01:25
Well, silver has a one plus charge, whereas sulfur has a two negative.
01:29
So we need ag2s, and our other product is going to be sodium with the nitrate, a positive one and a negative one.
01:39
Looking at the solubility rules, i'm gonna do that right now.
01:42
We see that ag combined with sulfide is insoluble.
01:47
That's going to form a precipitate.
01:50
We see that all nitrates, when we look at the solubility rules, all nitrates are soluble, so that would remain aqueous.
01:56
The other thing we need to do is balance this.
01:58
We have one silver on the left, but two on the right.
02:01
So we need a two in front of agno3, which gives us two nitrates.
02:05
So we need a two in front of nano3, and then that balances the sodium.
02:10
So this is our balanced equation.
02:12
So the first thing we want to know are the products...