- [ α ] is specific rotation in ____

- [α] is specific rotation in degrees

- α_obs is the observed rotation in degrees

- c is the concentration in (g/mL)

- l is the path length in dm

Note: Rotations measured at different concentrations and tube lengths can be converted to a standardized specific rotation using the following equation:

- where [α] is specific rotation in degrees, α_obs is the observed rotation in degrees, c is the concentration in (g/mL), and l is the path length in dm.

Note: A polarizer allows light waves oscillating only in a particular direction to pass through, producing plane-polarized light, as shown in Figure 2.12.

Note: A simple 180° rotation around a vertical axis, as shown in Figure 2.11, allows the compound to be superimposed upon its mirror image.

Note: For example, the C-1 carbon atom in 1-bromo-1-chloroethane has four different substituents. As shown in Figure 2.10, this molecule is chiral because it is not superimposable on its mirror image.

Note: Chirality can also be thought of as handedness. In fact, one of the easiest visualizations of chirality is to think of your own hands, as shown in Figure 2.9. Although essentially identical, your left hand will not be able to fit into a right-handed glove.

More cards in Chapter 2: Isomers