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Ch.17 - Aqueous Ionic Equilibrium

Chapter 17, Problem 119

In analytical chemistry, bases used for titrations must often be standardized; that is, their concentration must be precisely determined. Standardization of sodium hydroxide solutions can be accomplished by titrating potassium hydrogen phthalate (KHC8H4O4), also known as KHP, with the NaOH solution to be standardized. b. The titration of 0.5527 g of KHP required 25.87 mL of an NaOH solution to reach the equivalence point. What is the concentration of the NaOH solution?

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Hello. Everyone in this video we're trying to calculate for the concentration of R. L. I. O. H solution. So let's recall that at our equivalence point of a dehydration means that our moles of acid while she equal to the moles of base. In this case for our given problem here, that just means arm. One mole of K HP. Which this compound right here is going to equal to R one mole of L. I. O H. All right. So some things that we can calculate beforehand is our molar mass of K. H. P. That's going to equal to 204. g per mole. All right. So calculating for my moles of acid. So, we have given to us in the problem of 0. g. Let's go ahead and write that. So 0.8585g. We're gonna have to convert this into moles. How we can do this is by using our molar mass. So one more on top. In the bottom we'll have our mass. So 204.22 g. You can see that the g will cut out beautifully giving us the unit in moles. So that's going to equal to putting everything into my calculator. Later, I'll get the value of 4.2038 times 10 to negative three moles. And because we have the equivalence point of filtration, the most acid will equal to the molds a vase. So we'll also say therefore our morals um base, It's equal to the same thing. 4.238 times. Sandy -3 moles. If we can recall our concentration, The same thing as polarity. Polarity is our scientific way of saying concentration. That's going to equal two moles over volume. We're scrolling down a little bit here, We can say our 4.2038 times 10 to the -3 moles. We'll have 19.63 mm converting this into leaders. We have 10 to negative three liters and one minute later on the bottom and of course like it just cuts out the middle. Later units. Alright, so again, putting this equation into my calculator, I'll get the morality of 0.2142 capital M capital M. Is for charity. And that's our units against growing down just a little bit here. So we have we have just solved for the concentration of our L. I. O. H. Solution and that's equal to 0. moller. And this is going to be my final answer for this problem. Thank you all so much for watching