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17 Nov 2019
Question number 1, 4, 5, 6 and 7. I want those questions answered. CHEM 140 Questions, Experiment 2 Recrystallization Questions In a recrystallization from ethanol, acetylsalicylic acid (pure mp 137- 138°C) was melted on a melting point machine immediately after vacuum filtration, and found to have a melting point of 120-127 C. Why is the melting point not 137-138 C? Assume that there are no solid compounds present other than acetylsalicylic acid, and explain in terms of what affects melting points, and how. 1. 2. /Why should the funnel be stemless when performing a hot gravity filtration? Construct a flow chart showing the purification of aspirin. Begin with aspirin, soluble impurities, and insoluble impurities. 3 4. What is the purpose of evaporating some of the solvent before cooling to get crystals? 5. Drawing air through the crystals aids in drying them. How do we accomplish this? It is important when a vacuum filtration is finished to disconnect the vacuum hose before shutting off the water. What will happen if you neglect to do this? 6. 7. Would ammonium carbonate (smelling salts) dissolve better in water, or in ethanol? Why? as> 13 1ous (51-6 16
Question number 1, 4, 5, 6 and 7. I want those questions answered.
CHEM 140 Questions, Experiment 2 Recrystallization Questions In a recrystallization from ethanol, acetylsalicylic acid (pure mp 137- 138°C) was melted on a melting point machine immediately after vacuum filtration, and found to have a melting point of 120-127 C. Why is the melting point not 137-138 C? Assume that there are no solid compounds present other than acetylsalicylic acid, and explain in terms of what affects melting points, and how. 1. 2. /Why should the funnel be stemless when performing a hot gravity filtration? Construct a flow chart showing the purification of aspirin. Begin with aspirin, soluble impurities, and insoluble impurities. 3 4. What is the purpose of evaporating some of the solvent before cooling to get crystals? 5. Drawing air through the crystals aids in drying them. How do we accomplish this? It is important when a vacuum filtration is finished to disconnect the vacuum hose before shutting off the water. What will happen if you neglect to do this? 6. 7. Would ammonium carbonate (smelling salts) dissolve better in water, or in ethanol? Why? as> 13 1ous (51-6 16
Deanna HettingerLv2
1 Nov 2019