In this lab, we wanted to find the percent ionization of acetic acid in vinegar. To do this, we titrated a weak acid (acetic acid) with a strong base (sodium hydroxide). We began by filling up a burette to the zero point with 0.25 M NaOH and then we used a graduated cylinder to measure out 7.6mL of vinegar (CH3COOH) into a flask. Next, we added 20 mL of distilled water and a few drops of phenolphthalein (acid-base indicator) to the flask. We used a hot plate and magnetic stirring bar to stir our solution as we added drops of NaOH to the base-filled flask. We began by slowly adding in drops of acid, but as the pink color remained longer, we dropped the rate of drops even lower. Finally, we added NaOH drop by drop until we reached a very light pink solution.
 |
| The setup |
 |
| Our analyte at the equivalence point |
Our final percent ionization of vinegar was 0.46%. This percentage is a low number because acetic acid is a weak acid, therefore the reaction between the acid and the base doesn't result in 100% complete ionization and not many hydronium atoms are present in the solution.
No comments:
Post a Comment