Question

5. John and Jane used 0.70 g of NBS (N-bromosuccinimide) (mw = 177.98g/mol) and 0.48 mL of 1-methylcyclohexene (density = 0.811g/mL, mw = 96.17g/mol) in their preparation of the bromohydrin (Experiment 10). They obtained 0.70 g of crude bromohydrin (mw = 193 g/mol). After they split the product, Jane received a vial containing 0.40 g of the crude bromohydrin. She used the column chromatography to purify the crude product and obtained 0.30 g of pure bromohydrin. (a) Determine both percent crude yield and percent purified yield for the bromohydrin prepared by Jane. (b) Explain if the bromohydrin prepared by John has the same or different yields compared to those prepared by Jane. (c) Later John noticed that he had miscalculated the amount of NBS used in the reaction. 0.74 g instead of 0.70 g had actually been used. Explain how this will alter their yield calculation.