Asprin

Place on your blog the answers and steps (process) to this student's aspirin lab questions from Organic Chemistry I:
   "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).  What is my theoretical yield and my percent yield?"

	C7H6O3        +     C4H6O3        ->    C9H8O4       +  HC2H3O2
Grams	2.0g	5.0g	2.612g
Molar mass	138.12	102.09	180.15
Moles	.0145	.0490	.0145
Limiting reagent	x

2.0g of C₇H₆O₃  x         1 moles   _ =  .0145 moles of  C₇H₆O₃

                               138.12g

5.0g of C₄H₆O₃  x         1 moles   _ =  .0490 moles of  C₄H₆O₃

                               102.09g

.0145 moles of C₉H₈O₄  x      180.15g   _ =  2.612g of C₉H₈O₄

                                         Moles

Theoretical yield of C₉H₈O₄ is 2.612g

Percent yield is 2.1g / 2.612g x100 = 80.4%



March 23