 And we'll try this one here. So what was the concentration of sodium ions and phosphate ions B and one molar sodium phosphate? So this one is fairly simple, right? So you do need to know in this case this molecular formula. So this is the reason why we were learning reaction formulas in chapter 5, right? So when it says something like, so this formula would not be given to you here. It says what would the concentration, in fact a better way to word this would be what would the concentration of sodium ions and phosphate ions be when you dissolve sodium phosphate into solution to make one molar solution. So in order to be able to do that you would need to write this chemical equation here. So sodium phosphate, the reason you know that it looks like this is because you know the polyatomic phosphate PO4 3 minus. So this is one of the polyatomics that you have to know, okay? So the 3 minus there. And you know also that sodium is in group one, right? So it's a plus one charge. So in order to put these two things together you're going to need three of these to every one of these, right? And so when you're going to put it together it's like that, sodium phosphate, okay? So instead to dissolve that, so that means to begin with it was a solid into water. When you do that, that breaks up the salt into its constituent ions, right? So a lot of people want to keep this as Na with the 3 behind it, okay, as a subscript. So that's incorrect because that means that all of those Na's are stuck together, okay? So instead those Na's all break apart, right? So we've got three Na pluses like that and since we've dissolved them into water they're aqueous, okay? And we have one PO4 3 minus. Okay, so it said that the concentration of our solution, the concentration of Na3 PO4, well we'll give it one molar, I guess we don't need to give it any more sig figs. So what is it talking about? It's talking about one molar Na3 PO4, like that. Molar, remember that's the shorthand way of writing one mole per, one mole per liter. The action equation itself gives us these conversion factors that we can use for this particular problem, right? So this problem was asking us, well if we know the concentration of this, what's the concentration of this and what's the concentration of this, okay? So we're trying to figure out, well what's the concentration of sodium ions? We've got three sodium ions, okay? So we can write this. So for every one mole sodium ions is, all we use is this conversion factor, or this multiplied by this conversion factor, okay? So the original concentration, one mole PO4, one liter of solution, that seems like that. We still have the same amount of solution. We're just trying to figure out how many sodium ions we have. And we've got this conversion factor. So if we want to know sodium ions over here, there's three moles of sodium ions for every one mole molarity at one sig fig. It's going to be three molar and sodium ions, right? And you guys can probably do the same thing for phosphate ions. What would be the molarity of phosphate ions? One mole, right? So you would do the same exact thing. Any questions on that in particular? Pretty straightforward, right? So we're going to compare that in the next problem. We're going to do the same thing, but we're going to do equivalent ones per liter, okay?