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.

Explanation:

The equation to calculate the specific rotation () of a substance is:

Where:

In this case:

The specific rotation:

the molecules move in straight line until they collide with each other or with the walls of the container. collisions are perfectly elastic; when two molecules collide, they change their directions and kinetic energies, but the total kinetic energy is conserved.

explanation:

water and alcohols have similar properties because water molecules contain hydroxyl groups that can form hydrogen bonds with other water molecules and with alcohol molecules, and likewise alcohol molecules can form hydrogen bonds with other alcohol molecules as well as with water.