What type of solution contains equal concentrations of dextrorotatory and levorotatory compounds?

A solution that contains equal concentrations of dextrorotatory and levorotatory compounds is termed a racemic solution. In this type of solution, the optical activities of the two enantiomers cancel each other out, resulting in no net rotation of plane-polarized light. Dextrorotatory compounds rotate the light in a clockwise direction, while levorotatory compounds rotate it counterclockwise. When these two are present in equal amounts, the overall optical activity becomes zero, which is characteristic of a racemic mixture.

The other options do not accurately describe a solution characterized by equal concentrations of both types of enantiomers. A saturated solution refers to a solution that holds the maximum amount of solute at a given temperature and pressure but does not imply anything about enantiomer composition. A supersaturated solution contains more solute than can be dissolved at that temperature, and similarly does not concern itself with enantiomers. Lastly, chiral refers to molecules that are not superimposable on their mirror images and does not denote any specific mixture of those molecules; it describes the property of individual compounds rather than the specific combination of both enantiomers in a racemic mixture.