(4) 15. Penicillin has a specific rotation of +223. What would the measured angle of rotation be of a 0.00300 g.m solution, if it were measured in a 10.0 cm long polarimeter tube? C=· 30ã9] m (6) 16. A pure sample has a specific rotation of +490. A mixture of this sample with its enantiomer gave a specific rotation of +12o a. What is the mixture's % enantiomeric excess? b. what is the mixture's % (+) enantiomer? c, what is the mixture's % (-) enantiomer?
A student is using the polarimeter to analyze a solution containing a mixture of enantiomers. The student observes a rotation of -32.8º. Knowing the cell length is 10.5 cm, the concentration of the solution is 0.79 g/mL, and the specific rotation of the pure (-)-enantiomer is -53.6º, what is the percent enantiomeric excess of the (-)-enantiomer in the student's solution?