Posted by Jim on .
I need some help with calculating percent yield and percent purity of aspirin.
Here's my data (questions follow):
Mass of salicylic acid.., 2.0 g
Volume of acetic anhydride.., 5 mL
Mass of watch glass.., 22.10 g
Mass of aspirin and watch glass.., 28.01 g
Mass of aspirin.., 5.91 g
DETERMINATION OF PURITY
Mass of aspirin.., 0.34 g
Concentration of NaOH.., 0.1 M
Initial buret reading.., 0 mL
Final buret reading.., 15.8 mL
Volume of NaOH used.., 15.8 mL
Number of moles of NaOH required.., 1.60 x10^-3 mol
1. Calculate your mass percent yield of aspirin.
(actual yield, g/theoretical yield, g) x 100
Not sure what numbers I'd use here...
2. Calculate the percent purity of your aspirin.
(mass of aspirin, g (titration)/mass of aspirin, g (synthesis)) x 100
(0.34 g/5.91 g) x 100 = 5.8%
I'm pretty sure that's right, but not completely.
patience. Answered below on the original post.