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1. As shown in Figure \(\PageIndex{17}\), a potentiometric titration curve provides a reasonable estimate of acetic acid’s pK a. Show your calculations. Determin the mass of acetic acid in the vinegar that you titrated. Average volume of NaOH used = 7.93mL Moles of NaOH used = 1.5M x 7.93mL= 11.9mmol Mass of acetic acid in vinegar 11.9mmol x 60.0g/mol/1000 % CH3COOH in vinegar-0.80g x 100/5mL-16% CH3COOH 0.71g Why is it important to do multiple trials of a titration… The reaction is: CH 3 COOH(aq) + NaOH(aq) --> CH 3 COONa(aq) + H 2 O(l) Titration: an analytical procedure involving a chemical reaction in which the quantity of at least one reactant is … Rection of ethanoic acid and aqueous NaOH is a weak acid - strong base reaction. Final buret reading:(Titration 1) = 21.6 (Titration 2) = 23.41. This experiment is designed to determine the molar concentration of acetic acid in a sample of vinegar by titrating it with a standard solution of NaOH. written by: Heshan Nipuna, last update: 27/05/2020 So, we lose all of that, and so we've neutralized all of our acid too. If we titrate a solution of acetic acid with NaOH, the pH equals the pK a when the volume of NaOH is approximately 1⁄2V eq. Determine the oercentage by mass of acetic acid in vinegar. 3. During the titration of acetic acid and NaOH, pH value is changed. In contrast, methyl red begins to change from red to yellow around pH 5, which is near the midpoint of the acetic acid titration, not the equivalence point. So, if we think about starting with zero moles of acetate, and we lose 0.0100 moles of acetic acid, that turns into acetate. Just as with the \(\ce{HCl}\) titration, the phenolphthalein indicator will turn pink when about 50 mL of \(\ce{NaOH}\) has been added to the acetic acid solution. Calculate pH at the equivalence point of formic acid titration with NaOH, assuming both titrant and titrated acid concentrations are 0.1 M. pK a = 3.75. Answer to: What volume of 0.1751 M NaOH is needed to titrate 24.0100 mL of 0.2130 M acetic acid to the phenolphthalein endpoint? During a titration lab where 0.1 N of NaOH is added to 20 mL of acetic acid with the same concentration, the equivalence point occurred after adding about 70ish milliliters of NaOH (different peers acquired different values, ranging from 65 mL and 75 mL of NaOH). Volume of NaOH: (Titration 1) = 20.50 (Titration 2) = 20.86. So, this is our equivalence point for this titration. Acetic has only 1 H+ go contribute but I can calculate the moles of acetic to be approximately 2/60 = 0.033 repeating moles Sodium ethanoate (salt) and water are given as products. So, the Normality of NaOH is = to Molarity since there is only one equivalent of OH- ions. And if we're losing acetic acid, we're converting acetic acid into acetate. We lose all of this. In this experiment, acetic acid (CH 3 COOH) is the analyte and sodium hydroxide (NaOH) is the standard. At the equivalence point we have a … Also, this reaction is an example to weak acid - strong base neutralization reaction. Introduction Vinegar is a common household item containing acetic acid as well as some other chemicals. 2. Using the balanced equation, calculate the moles of acetic acid neutralized by NaOH.