1. (+)Tartaric acid has a specific rotation of +12.0. Calculate the specific rotation of a mixture of 68% (+)-tartaric acid and 32% acid (-)tartaric. [2] 2. The specific rotation of (S)-2-iodobutane is +15.90. [6] (a) Draw the structure of (S) 2-iodo butane. (b) Predict the specific rotation of (R)-2-iodobutane. (c) Determine the percentage composition of a mixture of (R)- and (S)-2-iodobutane with a specific rotation of -7.95 3. For each structure below, 19) a) draw all the stereoisomers. b) label each structure as chiral or achiral. c) give the relationships between the stereoisomers (enantiomers, diastereomers). (a) (b) H CH3 C-CH H CH3 CH CHO H OH . OH CH2OH CH, H CH3 CH , 4. When pure (R)-3,4-dimethylpent-1-ene is treated with hydrogen over a platinum catalyst, the product is (S)-2,3-dimethylpentane. [8] (a) Draw the equation for this reaction. Show the stereochemistry of the reactant and the product. (b) Has the chirality center retained its configuration during this hydrogenation, or has it been inverted