00:02
Hi there, to answer this question we need to know what a conjugate acid -base pair is.
00:15
So a conjugate acid -base pair refers to two species in an equation, one's going to be a reactant and one a product, and they differ by a single proton, or in other words h+.
00:36
The acid has it, its conjugate base does not, or vice versa.
01:03
We could start with a base and then its conjugate acid is going to have one extra hydrogen.
01:08
All right, so let's look at our pairs here.
01:13
Our first pair has hco3 with a negative charge and co3 with a two negative charge.
01:27
All right, well we see that these differ by just a single hydrogen.
01:32
If we remove this hydrogen then we get co3 two negative.
01:35
So this one is a conjugate acid -base pair.
01:38
We are looking for the pair that is not, so that's not our answer.
01:41
Number two, we have h2o and h3o+.
01:45
Ah, definitely a conjugate base, or base and its conjugate acid, because the h3o plus has one more hydrogen than the h2o.
01:57
So that is a conjugate acid -base pair.
01:59
Let's look at the third set.
02:02
Oh, this one's a mess.
02:03
C6h5nh2 and c6h5nh3+.
02:21
All right, so even though these are more complex, we see the only difference between the one on the left and the one on the right is a single hydrogen.
02:29
The one on the right has the hydrogen, so it's the acid in the pair, and the one on the left does not have the hydrogen, so it's the base in this conjugate pair...