Percent Acid in Vinegar Lab

Over the last few days my lab partner and I have performed the Percent Acetic Acid in Vinegar lab. By standardizing a solution of NaOH with the acid potassium hydrogen phthalate, or KHP, in a titration we were able to determine the molarity of the NaOH solution. Using this standard NaOH solution, we were also able to determine the percent of acetic acid, HC2H3O2 in commercial vinegar.



Adding distilled water to the Erlenmeyer flask in order to dilute the vinegar



After adding two drops of the indicator phenolphthalein we were able to titrate the solution


After all of the titrations were complete, the calculations for the percent acetic acid in vinegar could be made by calculating the average molarity of NaOH and plugging that in to find the molarity of the acetic acid. The molarity could then be multiplied by the molar mass in order to find the mass of solute in the solution. With this mass the percent acetic acid in vinegar can be determined by dividing it by the volume of the solution.

This was helpful in calculating the percent acetic acid in vinegar