For each of the following questions, assume that all measurements are made in 10-cm polarimeter sample containers, 

(a) A 10-mL solution of 0.4 g of optically active 2-butanol in water displays an optical rotation of -0.56°. What is its specific rotation? 

(b) The specific rotation of sucrose (common sugar) is +66.4. What would be the observed optical rotation of such a solution containing 3 g of sucrose? 

(c) A solution of pure (S)-2-bromobutane in ethanol is found to have an observed a = 57.3°. If [a] for (S)-2-bromobutane is 23.1. what is the concentration of the solution?