|  | Chapter 7 : Stereochemistry |  | 
1. Given that (R)-2-bromobutane has 
  a specific rotation of -23.1o , what is the specific rotation of 
  (S)-2-bromobutane  ? 
    
2. Using the data from Qu1, what is the optical purity and % composition of a mixture of (R)- and (S)-2-bromobutane whose specific rotation was found to be +18.4o ?
3. What about a mixture whose specific rotation was found to be - 9.2o ?