resolution of 1,2 dichlorocycohexane:
The compound was prepared by adding 6.6 gr of L-tartaric acid and 5.2 ml of racemic mixture in a conical flask, heated at 95 °C while stirring. The precipitate form was redissolved with hot water and the solution was allowed to cool down, crystals formed and were filtrated. After filtration a solid and a liquid part were separated.
The solid crystals were redissolved in 20 ml of 2 M NaOH, and the solution was extracted twice with 15 ml and 10 ml of dichloromethane. The extracted were then dried with sodium sulfate, and the solvent was evaporated. Yield and purity by polarimetry were calculated
Separately, the liquid form of the filtration performed previously, was mixed with 20 ml of NaOH, and extracted twice with 40 ml and 20 ml of dichloromethane. The extracted were combined and dried with sodium sulfate. Successively the solvent was removed. The yield and purity by polarimetry were calculated.
crystals mass after filtration (step 1): 3.84 g
liquid mass after filtration (step 1): I forgot to weight the flask, but the yield should be aroun 40%
mass of solid extracted after removal of solvent (step 2): 0.18 g
mass of salt from liquid after removal of solvent (step 3): 0.679 g
I dont understand if I have to calculate the yield from the mass of solid extracted after the removal of the solvent or I have to use the mass of crystals after filtration?
Alpha observed: 84.75
temperature: 26.6 °C
D= 589 nm
Alpha observed= -44.95
D= 589 nm
How do i calculate alpha and the concentration?