Molar Mass of an Unknown Acid Lab

Last week in chemistry class, we completed our third and final acids and bases lab to determine the molar mass of an unknown acid. In order to be able to do this lab, we had to write our own procedure. First, we added 100mL of NaOH to our buret and then mixed around .5 grams of KHP with water in a flask. After the KHP was dissolved, we added 3 drops of phenolphthalein to act as our indicator. Then we titrated this using the NaOH in the buret, until the solution turned and stayed pink. Then we recorded how much NaOH was used. After this, we repeated these same steps, but with around .2 grams of the unknown acid in our flask, instead of KHP. In order to get the unknown acid to dissolve in the water, we had to heat/stir the solution at the same time. This was a new experience, because we had never used an automatic stirrer before. Overall, this lab was interesting and a good conclusion to the unit using everything that we had learned.

Here is what the solution looked like on the hot plate as we were heating it: