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 (KHC 8 H 4 O 4 ), 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?

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

Ch.18 - Aqueous Ionic Equilibrium

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Ch.18 - Aqueous Ionic Equilibrium

Problem 119

Chapter 18, 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?

Verified step by step guidance

Identify the balanced chemical equation for the reaction: \( \text{KHP} + \text{NaOH} \rightarrow \text{KNaP} + \text{H}_2\text{O} \).

Calculate the moles of KHP used in the titration. Use the formula: \( \text{moles of KHP} = \frac{\text{mass of KHP}}{\text{molar mass of KHP}} \).

Since the reaction between KHP and NaOH is a 1:1 molar ratio, the moles of NaOH will be equal to the moles of KHP.

Determine the concentration of the NaOH solution using the formula: \( \text{Concentration of NaOH} = \frac{\text{moles of NaOH}}{\text{volume of NaOH in liters}} \).

Convert the volume of NaOH from mL to L by dividing by 1000, and use this in the concentration formula.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Titration

Titration is a quantitative analytical technique used to determine the concentration of a solute in a solution. It involves the gradual addition of a titrant (a solution of known concentration) to a sample until a reaction reaches its equivalence point, where the amount of titrant equals the amount of substance in the sample. This method is commonly used in acid-base reactions to find the concentration of an unknown solution.

Equivalence Point

The equivalence point in a titration is the stage at which the amount of titrant added is stoichiometrically equivalent to the amount of substance present in the sample. At this point, the reaction between the titrant and the analyte is complete, and it is often indicated by a color change in the solution due to an indicator. Understanding the equivalence point is crucial for accurately calculating the concentration of the unknown solution.

Molarity

Molarity is a measure of concentration defined as the number of moles of solute per liter of solution. It is expressed in units of moles per liter (mol/L). In the context of titration, calculating the molarity of the titrant (in this case, NaOH) is essential for determining how much of the titrant is needed to completely react with a known amount of the analyte (KHP), allowing for the standardization of the solution.