1 / 8

Recrystallization and Melting Point

Recrystallization and Melting Point. Summer 2012. Purification and Characterization. Purification: separation of target compound from impurities Characterization Identity: Do I have what I think I have? Purity: How pure is the compound?. Recrystallization. Purification for solids

rad
Download Presentation

Recrystallization and Melting Point

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Recrystallization and Melting Point Summer 2012

  2. Purification and Characterization • Purification: separation of target compound from impurities • Characterization • Identity: Do I have what I think I have? • Purity: How pure is the compound?

  3. Recrystallization • Purification for solids • Useful for • Large samples • Final purification step • Based on differential solubility

  4. Practical Aspects Impure Solid  Dissolve Recrystallize Filter www.whfreeman.com/mohrig3e then Movies and Spectra  Williamson Movies  5.3 Recrystallization (macroscale) (Also look at others, such as Drying Organic Liquids and Melting Points)

  5. Recrystallization: Theory • IMF in solids • Temperature dependence • Equilibrium process in slow crystal formation

  6. Important Points • Choice of solvent • Mixed solvents • Maintaining hot solvent • Safety when boiling • Hot filtration • Inducing crystallization • Washing crystals • Too much/too little solvent • Oiling out

  7. Melting Point • Physical property to characterize substance • Identity • purity capillary Melt-temp

  8. Theory and Application • Theory • Pure crystals and impure crystals • Intermolecular Forces • Lattice energy • Application • Depressed MP • Broad MP • Mixed MP Eutectic mixture

More Related