We're looking to mix the solution of Precor inc acid with sodium hydroxide. Okay. And we're looking for the concentration of acid at equivalence point. We just need to remember that moles of acid and moles of based equal each other at equivalents. Okay, So then if we write that out fully, you know that C. A. So concentration of us at times while we have acid equals concentration of base times volume of space. So let's just rearrange and we're absolutely looking for volume. It's changed out there. You have volume or concentration of acid. They're looking for volume. So we'll use this relationship here. Okay? So if we just multiply what we were given and divided by penetration of acid, Okay, we end up with here is 0.0 3 8 leaders of acid is required to get this solution to equivalents. Next example we have a solution of some magnesium hydroxide and you're mixing it or not a solution. A mass. We have 2.87 g of this stuff And we're going to put it into a 0.128 smaller concentration of some hydrochloric acid. Yeah. So we'll start off by recalling magnesium hydroxide, Molar mass which is 38 g promote approximately. And that will get us Um Malls of 0.0492. Yes. Okay. So if we're looking for the volume to get to equivalence, we'll just use this relationship and free. But so you just plug in all the components here. So understanding is zero 7687 leaders will take us to equivalents. Next up we will look at another reaction. Okay, We're going to take silver nitrate and mix it with some potassium chloride until we get some silver chloride as precipitate. Yes. What in fact do we have? So you know the volume of the silver nitrate solution? 0.0258 leaders. And we actually have some solid potassium chloride. It's 0.785 g. Okay, so again, we were well um search up the molar mass of potassium chloride to be 74.551 g per mole yielding a number of moles Of 0.01053. All right, so now we have malls. We have volume. We can solve for a concentration kept by just taking this these ones here, over the volume here. And what we end up Getting is zero Actually 0.48 40813 most per liter. Lastly we have another I'm not equilibrium kind of a reaction actually neutralization with as recalled acid. Okay. And Saudi or potassium hydroxide. Okay, so the concentration we have of the asset Is your .10 eight months And the volume is your .0453 leaders case. That gives us a mold. If you just multiply the two Of 0.00489 moles. All right. So the only thing we know about the potassium hydroxide here is that it's smaller mass 56 g per mole. Yes, but we do have moles because we know, as I said earlier, most of acid equal smells of base. So then if we take our more mass multiplied by moles will get actually the mass That is required to reach equivalent point which is 0.27 four or 5 g. I just want to play those numbers there.