BIO Optical Activity Optically active molecules have the

Chapter 25, Problem 79P

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Problem 79P

BIO Optical Activity Optically active molecules have the property of rotating the direction of polarization of linearly polarized light. Many biologically important molecules have this property, some causing a counterclockwise rotation (negative rotation angle), others causing a clockwise rotation (positive rotation angle). For example, a 5.00 gram per 100 mL solution of l-leucine causes a rotation of −0.550°; the same concentration of d-glutamic acid causes a rotation of 0.620”. (a) If placed between crossed polarizers, which of these solutions transmits the greater intensity? Explain. (b) Find the transmitted intensity for each of these solutions when placed between crossed polarizers. The incident beam is unpolarized and has an intensity of 12.5 W/m2.