00:01
For these problems, you want to look at the species that is donating a proton, and then the species that is gaining the proton.
00:08
And so, according to the bronstead -lauri definition of acids and bases, acids donate protons and bases accept protons.
00:18
So in this first case, a proton is leaving this hydrated aluminum species and going to the water.
00:25
So on the other side, you have h3o plus.
00:28
The water is gained a proton.
00:29
And the aluminum species has lost a proton.
00:33
So key here is its charge has decreased by one.
00:37
It's gone from 3 plus to 2 plus.
00:39
The water had zero charge, and now it's gone to plus because it's gained that proton.
00:44
So that means the aluminum species is the acid because it donated the proton.
00:49
The water is the base because it accepted the proton.
00:54
And on the other side of the equation, which you would basically do is look at the same logic and go in reverse.
01:01
So in this case, the h3o plus proton is going in this direction because water would have h3o plus in this direction...