 Okay, so this problem says the following pictures represent solutions that contain weak acid, which we call HA, and its conjugate base, H, are A- Okay, so potentially they have these things in them, and you can see that in the picture Which of the solutions are buffer solutions is the first question, okay? So remember what we have to have in order to have a buffer solution We have to have a mixture of HA and A- its conjugate base, okay? Or the salt of its conjugate base, which the cations aren't being represented in these pictures But anyway, so when we're looking at these different representations In order to have a buffer solution, we have to have this present and this present, okay? So if I look here, I only see HA present So I would say that this is not a buffer solution, okay? But in this case, right, I see HA and A- present So it's a solution that has some of the concentration of HA and some concentration of A- So that would be considered a buffer solution, okay? So let's write it down, so this is non, this is a buffer, and what about the other one? It's also a buffer Yeah, it's also a buffer for the same reason, right? So we see A- and HA both present Okay, the next question asks, well, which of these buffers has the highest buffer capacity? Okay, and do you recall what we said about buffer capacity in our lecture? That the one Higher concentration Yeah, the higher concentration, okay? So we want the one that has equivalent amounts of the acid and its conjugate base are close to equivalent amounts, that gives us a good buffer and the one with the highest concentration of those two things, right? So which one would have the highest buffer capacity? The one in the middle The one in the middle, right? Why? Because if we count, right? One, two, three, four, five, six A-s, one, two, three, four, five, six HAs, right? So six and six and here we have one, two, three, four, one, two, three, four So this one's more concentrated than this one So this has the highest So what does buffer capacity mean? Remember, it's like resistance to pH change, okay? So if I add acid or base, this one will take longer to change the pH than this one would and of course this one wouldn't have any buffer capacity Okay, questions? Okay, go