A student performing this experiment forgot to add phenolphthalein solution to the vinegar solution before beginning the titration after adding 27 mL of NAOH solution he realized his error and added the indicator. The solution turned bright, pink suggest a procedure the student could fall to salvage the titration
The student should start over by adding a known amount of vinegar solution to a clean flask and then adding the phenolphthalein solution. Next, re-fill the burette with fresh NaOH solution and carefully titrate the vinegar solution until it turns pink, indicating that all the vinegar has reacted with the NaOH. The student should record the volume of NaOH solution used and repeat the titration two more times to ensure accuracy. Finally, they can calculate the average volume of NaOH solution needed to neutralize the vinegar, and use this value to calculate the concentration of the vinegar solution.
