Lab 5 Purification and Analysis of Aspirin Name Pre-Lab Exercise: Introduction The crude acetylsalicylic acid from last week will be purified and then analyzed using TLC OH Acetylsalicylic Acid True 1. Answer true or false regarding today's experiment: (1 pt each) a. Crude product means that it still contains starting material b. Salicylic acid is a liquid at room temperature c. The recrystallized product should give two spots on the developed TLC d. C o functional group is called an ether e. While spotting the TLC plate, one must keep the spot small and concentrated tulse True 2. TLC will be used to analyze the crude versus purified product. Complete the TLC plate by doing the following: -label each arrow with the special name given to each line indicated (2 pts) -assuming the same solvent system as before, draw in a position(s) for today's purified product (1 pt) Solvent front Bruseline 3. Using words and full sentences, describe how to calculate the Theoretical Yield of a product in a 1:1 molar ratio. Points will not be given for writing out one long conversion factor! (2pts) Lab 5 Purification and Analysis of Aspirin Name Post-lab Questions (10 pts total) 1. During the recrystallization procedure, explain why the minimum amount of hot ethanol was added, and not excess hot ethanol. (3 pts) We added a 2ml ethanol to the crystals to dissolve it 2. Explain why it is important to complete a TLC plate slowly and carefully. (2 pts) 3. A crude unknown compound (6.8 g mass, with molar mass 172 g/mol), was recrystallized. The resulting purified mass was 4.2 g. Calculate the percentage recovery after recrystallization. (Show full working below). (3 pts) 4. Consider this two-week experiment, and compare and contrast your crude product, versus your recrystallized product. (2 pts)