Polarimeters are so sensitive that they can measure
rotationsto the thousandth of a degree, an important advantage when
onlysmall amounts of a sample are available. for example, when
7.00mgof ecdysone, an insect hormone that controls molting in
thesilkworm moth, was dissolved in 1.00 ml of choloroform in a
cellwith a 2.00 cm path length, an observed rotation
of+0.087o was found. calculate [a]d
forecdysone.