Table 1. Unknown Alkanes. Chem 2315 Lab Manual (Experiment 2) Table 2. Unknown alkenes. Write the unknown alkene reaction with Br2 in methyl benzoate, showing the product structure. If you had an alkane unknown, write the product that would be expected for cyclohexene. (See Wade, 9th ed., section 8-8.) (unknown alkene, or cyclohexene) (bromination product of unknown alkene) in pent ane After fractional distillation a student characterized his unknown as follows: small scale fractional dist. bp corrected for altitude =67.268.9C small scale bp corrected for altitude =65C small scale density (syringe) =0.651g/mL refractive index corrected to room temperature =1.3756 bromine/methyl benzoate test = remained reddish/brown (did not turn colorless)