Standardization of NaOH Lab Procedure

Procedure:

1) The apparatus was assembled.
2) The buret was then rinsed with some NaOH solution.
3) About 0.7 g to 1.0 g of KHP was measured on a scale.
4) The KHP was transferred to a flask.
5) To ensure that all the KHP was transferred to the flask, a wash bottle was used to rinse the plastic tray into the Erlenmeyer flask with the KHP.
6) Distilled water was used to rinse the plastic tray. About 50 mL of distilled water was added to the flask to dissolve the KHP.
7) After the KHP dissolved, NaOH was added to the buret and initial volume of resulting solution was measured.
8) Two drops of phenolphthalein was added to the flask.
9) The KHP was titrated with NaOH until the solution in the flask turned pink indicating that the end point had been reached.
10)The sides of the flask were occasionally rinsed down to ensure that all of the acid and base remained in the bottom of the flask.
11)After the KHP was titrated and the end point was reached, the final volume of NaOH solution in the buret was measured.

Data:

Mass of the KHP0.809 g
Starting Volume of Buret4.02 mL
Final Volume of Buret44.10 mL
Volume of NaOH drained40.08 mL