Experiment 8 - Equivalent Weight of an Unknown Acid

Procedure:

Part B - Acid-Base Titration

1. Obtain about 100 mL of standardized base solution in a clean and dry beaker. (The oven may be used to dry the beaker.)
2. Acclimatize and fill the buret with the base solution.
3. Transfer about 50 mL of the acid solution into a clean and dry 100 mL beaker. (The oven may be used to dry the beaker.)
4. Pipet 25.00 mL of the acid solution into an Erlenmeyer flask. Add about 3 drops of phenolphthalein indicator solution to the acid solution in the flask.
5. Add the sodium hydroxide solution in the buret to the acid solution in the flask until the end point is reached.
6. Read the buret carefully to determine the quantity of base used to reach the end point. Record the volume of the base solution used.
7. Repeat the above procedure until two results are obtained which agree within +/- 0.10 mL.