Today:. Quiz Comments Practice for Melting Point Ranges and Recrystallization Introduction to Molecular Modeling (Lab today is in SEGA lab Science249).
(Lab today is in SEGA lab Science249)
Melting point ranges for mixtures of compounds A and BPhase DiagramWhat is the mp. and mol% composition of the eutectic mixture?What is the mp. range of mixture X?
Solid A and B
Solvent Sol. Of C at 20o Sol of C in hot solvent
Water slightly soluble soluble
Ethanol soluble soluble
Acetone soluble soluble
Benzene slightly soluble soluble
Pet. Ether insoluble insoluble
1) Which single solvent(s) could you use for recrystallization?
2) Suggest a mixed solvent pair that you could use instead.
1.000g of caffeine completely dissolves in a minimum of
Assume that you are recrystallizing 2.000g of impure caffeine.
After one recrystallization from 30.0 ml of water you ended up with 1.200 g of purified caffeine. How many grams of caffeine were left in the cooled water? (careful …)
If you reduced the volume of the mother liquor to 5 ml, how many grams of caffeine would be left in solution in the cooled solution?
Hybridization of C
Bond length, angle, dihedral angle; staggered and eclipsed conformations
Conformations of cyclohexane; axial , equatorial substituents
We’ll do MM Exps. 1, 2, 4, only