Assignment #9

"I started with 2.0 g of salicylic acid and 5 g of acetic anhydride and I got 2.1 g of acetylsalicylic acid (aspirin).  1) What is my theoretical yield and my percent yield?"

-first you are going to find which one is your limiting reagent by converting each mass (salicylic acid and acetic anhydride) into moles of aspirin. Which ever one produces the smallest amount of moles will be the limiting reagent.
2.0 g C7H6O3 --> .014 mol aspirin
5.0 g C4H6O3 --> .049 mol aspirin
So the limiting reagent will be C7H6O3. Now you will use this to calculate how much grams of aspirin will be produced. This will be your "theoretical yield" After this is found you will divide the actually yield you produced by what you should have produced to get your percent yield.
2.1 g / 3.77 g = .557

The percent yield will be 55.7%