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..ll GoSmart 9:18 PM 7 73% Х CHM 103 Lab 3 Acid Base... + U Experiment 3 ACIDS AND BASES: ANALYSIS Learning Objectives Upon completion of this experiment, Mudents will have experienced 1. The determination of the percent by mass of acetic acid in vinegar 2. The determination of the molecular mass of an unknown acid Text Toples Acids and buses, indicators, titrations Notes to Students and Instructor The solution of sodium hydroxide prepared last week will be used to determine the percent by mass of acetic acid in vinegar and to determine the molecular masofan unknown acid Discussion Have you ever tasted wine that has gone sour? The taste is due to the presence of acetic acid which results from the oxidation of the ethanol in the wine. In fact vinegar is produced by fermentation of sugar to ethanol followed by bacteria catalyzed oxidation of the ethanol to notic acid. One question that a chemist might be confronted with is how much acetic acid is present in the view This is just one of the questions commonly encountered by chemists working in analytical laboratories. Another challenge might be the identification of an acid in a sample. The determination of its molecularms can go a long way toward facilitating this identification. The amount of acetic acid in vinegar and the molecular mass of an unknown acid can be determined by titration with a standardized base. These are the topics for today's experiment. Procedure A. Titration of vinegar. Because Vinegar is close to 1 Moetic acid, it is advisable either to quantitatively dilute the vinegar or titrate only 5,00 ml. quantities to avoid using more than 1 buret full of sodium hydroxide. The use of 5.00 mL delivered with a volumetric pipet is