How many milliliters of 0.105 M HCl are needed to titrate each of the following solutions to the equivalence point: (a) 45.0 mL of 0.0950 M NaOH? (c) 125.0 mL of a solution that contains 1.35 g of NaOH per liter?

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Hello. Everyone in this video we're calculating for the middle layers of K. O. H. Needed to titrate our hbr at the equivalence point. So first things first, what I wanna do is right on my chemical equation, that's very good for any stock geometry that we have to do. And just to see what we're dealing with and what goes on in this reaction. So, first things first, like I said, we are going to go ahead and write our chemical equation on a starting reagent side. We have our H. B. R. That's going to go ahead and react with R N. A. O. H. This is a double displacement reaction. So on the product side we will get first R N. B. R Followed by our H. 20. All right. So another thing we have to go ahead and recognizes the concentration um unit of this capital M. Which is equal to moles over leaders. Alright, so now let's go ahead and calculate for our concentration of hBR. All right, so starting off with my grams of H B. R. So we have 5.10 g of H B. R. It says that the solution contains this amount of hBr per leader. Super. One leader. Then what I'm gonna do is go ahead and use the molar mass of our HBR to go ahead and get the most of my H. B. R. So one mole of H B. R. On top and then 80.91 g of H b are on the bottom. We see that the grams of H B. R. Will cancel. And the units that we are left with is moles over leaders. And that's exactly the unit of concentration that we are using in this problem. So putting the numerical values into my calculator, I would get the total of 0.6303 molars of H. B. R. Okay. Now separate calculation label this as step four. So we're calculating for the concentration now. So milliliters of the our K. O. H. Solution. Okay, so first things first we have the 25 ml of solution. I'm gonna want to convert this into leaders. This is because we're dealing with our polarity unit. So we have one liter of solution on top And 1000 ml of solution on the denominator that the millions of solution will cancel out. Then I'm gonna go ahead and use the concentration of HBR that we just calculated for right here. So again, it's Capital M equal to moles over leader. So we have a conversion. So that's 0.06303 moles of HBR for every one liter of this solution. Keep so that cancels out. Then we're gonna go ahead and do a multiple ratio. And this is why we wrote the chemical equation here. So we want our units that's in terms of hBR right now to be in terms of R K O H. So it's a 1 to 1 ratio for all of our agents in this chemical equation. So we have then one mole of H. B. R. And one mole of r K O H. Again we can see that the moles of H. Bar will cancel. And last step here that we have is we're gonna go ahead or second to last step. Actually we're gonna go ahead and use our polarity or concentration of co H. Given to us in the problem. So we have our 0. 550 moles of K. O H over one liter. So go ahead and cancel. The moles are K. O. H. And be left with our leaders. Let's just go ahead and scroll down a little bit to have more space. So if I put that onto my calculator, I would get everything in terms of leaders. But the question once milliliters, so we'll actually continue our calculations may be on the bottom here in the second row. So again we want to cancel the units of leader. So I put that on the bottom. So attention negative three liters for one millimeter And we see that the units of leaders will cancel out, giving us everything in terms of our Millimeter unit. So as for our numerical values, I'll go ahead and put everything into my calculator and once I do so I get the value of 28.7 and units of course being ml. And this right here is going to be my final answer for this problem. Thank you all so much for watching

How many milliliters of 0.105 M HCl are needed to titrate each of the following solutions to the equivalence point: (a) 45.0 mL of 0.0950 M NaOH? (c) 125.0 mL of a solution that contains 1.35 g of NaOH per liter?

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Key Concepts

Titration

Molarity (M)

Stoichiometry