1. Aspirin Analysis # 24

2. What are we doing today We are going to use a spec. 20 to determine the absorbance of our tablet. Once we know the absorbance we can determine the strength of our aspirin. Remember use the equation of line. To help determine the absorbance, we complex the aspirin.

3. Procedures Obtain, wash, and dry with acetone a mortar and pestle Obtain and accurately determine the mass of a aspirin tablet. Grind up your aspirin and place it in a 125 mL. Erlenmeyer flask. Add 10 Ml. Of 1. M NaOH and about 70 mL. Di. H 2 O Place the flask on a hot plate and warm the solution while swirling. Warm the solution until it boils. Rinse the flask down with Di. water Filter the solution into a 250mL. round bottom flask. Mix very thoroughly.

4. Procedures Continued Pipette 1 mL. of your solution into a 25mL. graduated cylinder. Add 0.020M IronIIIChloride solution and fill to the 20mL. line. Mix thoroughly Follow procedures on spec. 20 to determine absorbance.

5. Table 24-1 Calibration Graph Data Remember.898 actually means.898 X10 -4 M of Complex X 10 4 Absorbance.898.146 1.78.310 2.660.470 3.550.620 4.440.780

6. Lou Tisone Chem116-30 Fall-06

7. Due Next Week Two graphs #1 absorbance Vs. M x10 4 from the data I gave you # 2 Abs Vs. Mg./ Tablet you must calculate Do two trials ( two different tablets) Complete table 24-2 Answer questions 2-4

8. Lou Tisone Chem116-30 Fall-06

9. Help with table 24.1 Convert from Molarity to mg/tablet Ex #1.898X10-4 You must do the same for the rest of the data so you can make the second graph

10. Table 24.2 Trial # 1 Mass of my aspirin is.370grams, and abs =.482 from my calibration graph # 1 y = 0.1759X-0.0015 Don’t forget X10 -4 the actual answer = 2.76X10 -4 M

11. Mg Aspirin / Tablet table 24.2 Percent Aspirin / Tablet Weight of entire tablet = 0.370g or 370mg