Question

Procedure:

Re-Write this procedure in 3rd person past tense.

1. Fill the burette with sodium hydroxide solution.

2. Using the pipette, measure 10 mL of an unknown acid solution into a clean, dry flask. Add 2-3 drops of phenolphthalein and swirl gently.

3. Place the flask on the retort base on a white paper.

4. Record the pH of the acid using an electronic pH probe before titration begins.

5. Titrate the acid solution with sodium hydroxide solution until the endpoint is reached. Record volume readings of titrant. *See reference sheet for detailed instructions.*

6. Using a pH probe, measure the pH after 5mL of base has been added.

7. Repeat steps2-3 until you have three consistent results within 0.5 mL of each other. See your raw data tables (separate file) for average raw data.

8. Using a pH meter, measure the pH of the solution in the Erlenmeyer flask once the end point is reached.

9. Using a pH meter, measure the pH of the solution in the flask after 2 mL of base has been added beyond equivalence.

10. Dispose of all solutions as directed by your teacher. Return equipment and materials to their proper location after they have been rinsed well.

Answer 1

1. Burette filled with sodium hydroxide solution.

2. 10mL of an unknown acid solution measured into a clean dry flask using pipette. 2-3 drops of phenolphthalein added and swirled gently.

3. Placed the flask on the retort base on a white paper.

4. pH of the acid recorded using an electronic pH proble before titration began.

5. Acid solution titrated with sodium hydroxide solution until the end point reached. Volume readings of titrant recorded.

Saw reference sheet for detailed discussions.

6. The pH measured after addition of 5mL base using pH probe.

7. 2-3 steps repeated until they had three consistent results within 0.5mL of each other.

Saw their raw data tables (separate file) for average raw data.

8. The pH of the solution measured in the Erlenmeyer flask once the end point was reached using pH meter.

9. The pH of the solution in flask measured using pH meter after 2mL of base had been added beyond equivalence.

10. All of the solutions disposed as directed by their teacher. Equipment and materials returned to their proper locations after they had been rinsed well.