Optical Activity of Sugar?

[Nik]

An optically active molecule, like sugar, will rotate the plane of polarization through an angle that is proportional to the thickness of the sample and to the concentration of the molecule. To measure the concentration of a given solution, a samle of known thickness is placed between two polarizing filters that are at right angles to each other. The intensity of light transmitted through the two filters can be compared with a calibration chart to determine the concentration. a.) What percentage of the unpolarized lighht will pass through the first filter? b.) If no sample is present, what percentage of the initial light will pass through the second filter? c.) When a sample is placed between the two filters, the intensity of light emerging from the second filter is 40% of the unpolarized intensity. Thru what angle did the sample rotate the plane of polarization?A 2nd sample has 1/2 the sugar concentration of the 1st sample - what is the light intensity emerging from the second filter?