please help me solve this lab

Weigh out 5.0 g of salicylic acid and place in a 250 ml Erlenmeyer flask. Measure out 10 ml of acetic anhydride and add this to your flask. Be sure to do this in the hood and wear your goggles. Don't let the acetic anhydride contact your skin and don't get the vapors in your eyes. Carefully add 5 phosphoric acid, a catalyst, to the flask and swirl to mix everything thoroughly. Still in the hood, let the mixture sit for about 10 min. in a beaker of warm water (heated to approximately 70-80 oC) After heating, cautiously add 50 drops of distilled water. Add 20 ml of distilled water. Take your Erlenmeyer flask back to your lab table, and cool in an ice bath, to allow for crystallization of your product. If crystals do not appear, you can scratch the walls of the flask with a stirring rod to help crystallization. Filter the solid aspirin through a piece of pre-weighed filter paper using a Buchner funnel and a water aspirator.

what is the percentage yeild? accorrding to the formula given in the figure?

Procedure: Weigh out 5.0 g of salicylic acid and place in a 250 ml conical flask. Measure out 10 ml of acetic anhydride and add this to your flask, be sure to do this in the hood. Still in the hood, carefully add 5 drops of conc. H2SO4, a catalyst, to the flask and swirl to mix everything thoroughly. Heat the mixture for about 10 min. in a warm water bath (70- 80 C). Add 50 ml of distilled water and cool in an ice bath, if crystals do not appear, you can scratch the walls of the flask with a stirring rod to induce crystallization. Filter the solid aspirin through a piece of pre-weighed filter paper. Calculation: Percentage Yield = Practical wt. x 100 Theoretical wt. Calculation: Mwt. Wt. Salicylic acid 138.12 5 g Acetyl salicylic acid 180.15