Report Evaluation TOTAL Chem 209 Lab Report Experiment 2: Crystallization Student Name______________ Date_____________ Student ID #_______________ Section___________ A-Selection of a crystallizing solvent I-Purpose: II-Table of Reagents: Compound Formula M.Wt. (g/mol) Melting point (ºC) Boiling point (ºC) III-Results: Compound Water Cold Hot Toluene Cold Hot Ligroin Cold Hot Best solvent for Recrystallization IV-Discussion of Results: B- Recrystallization of Acetanilide I-Purpose: II-Table of Reagents: Compound Formula M.Wt. (g/mol) Melting point (ºC) Boiling point (ºC) III-Results: Structure of acetanilide Mass used (g) Mass recovered (g) % Recovery Acetanilide Melting point Crude Pure IV-Discussion of Results: C- Decolorization of Brown Sugar I-Purpose: II-Table of Reagents: Compound Formula III- Observation: IV-Discussion of Results: M.Wt. (g/mol) Melting point (ºC) Boiling point (ºC) E-Answer to Questions: 1. Would you recommend suction filtration for a solution in which ether is the solvent? Explain. 2. Why is it important to minimize evaporation during the filtration of the hot solution? 3. An organic chemist has an impure solid (X) which is soluble in water to the extent of 3 g per 100 ml of water at room temperature and 15 g per 100 ml of water at 100 °C. 10 g of X has 1 g of impurity A (A has the same solubility in water as X) and 0.40 g of impurity B (B is insoluble in water). How could you purify X? How many grams of pure X could be obtained after one recrystallization from water? 4. The solubility of an organic material A in 100 ml of acetic acid is shown in the following table: Temperature (°C) 20 30 60 80 100 110 118 Mass (g) 0.15 0.20 0.25 0.40 0.50 0.65 3.00 Two students recrystallized 10 g samples of A from acetic acid, the first dissolving A at 100 C and filtering at 20 C, the second dissolving the acid at 110 C and filtering at 30ºC. Calculate the quantity of acetic acid each student was required to use and the percentage recovery of A possible in each case.