Science Buddies: "Ask an Expert"

For a lab I used the base NaOH in a titration to determine the concentration of acetic acid in a sample containing 5 mL vinegar and 20 mL water. The results were a 28.5 mL end point with a pH of 2.88. Now that I have these values, how can I determine the acetic acid concentration? Please give me a thorough equation

Hi joshlikesblue,

In this acid/base reaction one mole of acetic acid reacts with one mole of NaOH. The titration endpoint is reached when you’ve added enough NaOH to react with all of the acetic acid. The number of moles of NaOH added is equal to the endpoint volume (28.5 mL) multiplied by the concentration of the NaOH solution. This result is the same as the number of moles of acetic acid in your 5 mL sample of vinegar.

For more information you might want to review the project procedures described here:

https://www.sciencebuddies.org/science- ... #procedure

I hope this helps. Please post again if you have more questions.

A. Norman