Determining the Percent of Acetic Acid in Vinegar

Titration is a procedure used for determining the concentration of an acid or a base by neutralizing a known volume of the acid or base with a solution of a standard base or an acid. A standard solution is one whose molarity has been accurately determined experimentally. 

In a titration, one solution is added slowly to the other until the equivalence point is reached. At the equivalence point of a neutralization reaction, the moles of acid and moles of base are equal. An indicator, placed in the reaction mixture, tells you by means of a color change, when the equivalence point has been reached. Your experimental data—the volume and molarity of the standard solution and the volume of the unknown acid or base solution—are all that you need to calculate the molarity of the unknown acid or base. 

In this activity, you will first standardize a NaOH solution by using the solution to titrate a known mass of oxalic acid (H2C204). Then, you will use your standardized solution to titrate a sample of vinegar. Vinegar is a solution of acetic acid (HC2H302). From your titration data, you will be able to calculate the number of moles and the mass of the acetic acid in your vinegar sample and determine the percent of acetic acid in vinegar. 

100-mL graduated cylinder ring stand burette burette clamp balance label 

Briefly explain what happens in a neutralization reaction. 

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