1. Mustard Titration Mrs. Wilson
Tuesday 5-10 and Friday 5-13
Mustard Titration
Mrs. Wilson

2. Objectives
Titrate a mustard solution in order to determine the % by mass of acetic acid present in yellow mustard.
Homework:
Unit 6 Exam – Monday 5/16 – prepare one (1) 3 by 5 index card. A review + concept map is posted. Review answers will be posted by the end of the day today.
WPP Presentations – Wed 5/18 (proposal due for all groups on this day)

3. Mustard Titration
Objective: Titrate (react) a solution of yellow mustard with M NaOH. Calculate to determine the % by mass of acetic acid in mustard. Titrate FOUR times – one time just to practice and three that count. You should NOT need more than 5 mL to reach endpoint.
Your lab MUST be completed and turned in this period, including the cleanup. One handout per group. It is still expected that all members will contribute fairly to the lab work and calculations.

4. 0.50 M NaOH goes into buret
** Only fill to or below the line – NOT ABOVE THE LINE. You don’t have to fill it all the way up.
** You must record one uncertain digit for all volumes.
~3 g yellow mustard + water in flask
** Weigh empty flask
** Add mustard
** Re-weigh flask + mustard
** Add some water to make a mustard solution
** No indicator required – solution will turn orange at endpoint

5. General procedure:
Prepare buret. (Follow directions in 6.10 or recall the video). Waste goes into the large waste beaker.
Fill your buret with M NaOH to or below the line. USE A FUNNEL and make sure the stopcock is CLOSED. Record initial volume of NaOH. Use one uncertain digit.
Weigh flask; add mustard to flask; weigh again; add some water.
Set up buret in buret clamp on ring stand.
Place flask under stopcock. Open stopcock and add NaOH until solution JUST turns orangey-red. Go dropwise as you get closer to endpoint.
Record final volume of NaOH. Use one uncertain digit.
Clean flask. Re-fill buret with base if you have to. Repeat for a total of 3 trials. Be very careful. Your lab grade does depend on your results.