Question

Racemic mixture

Hint:

Racemic mixture = 50:50 mixture of enantiomers → optically inactive.

Answer 1

Step 1: Understanding the term "racemic mixture."
A racemic mixture, also known as a racemate, is a mixture that contains equal amounts of two enantiomers (optical isomers) of a chiral compound. These enantiomers are non-superimposable mirror images of each other.

Step 2: Key features of racemic mixtures.
- The two enantiomers in a racemic mixture have the same physical properties such as boiling point, melting point, and solubility, but they differ in their ability to rotate plane-polarized light. - Since the enantiomers rotate plane-polarized light in opposite directions, the effects cancel each other out in a racemic mixture, and the overall mixture shows no optical activity.

Step 3: Example of a racemic mixture.
A common example is the racemic mixture of \( \text{(+)-lactic acid} \) and \( \text{(-)-lactic acid} \), which is a mixture of the two enantiomers of lactic acid. This mixture does not show any optical rotation, as the rotations of the two enantiomers cancel each other out.

Final Answer: A racemic mixture is a 1:1 mixture of two enantiomers, where the optical activities of the enantiomers cancel each other out, resulting in no net optical rotation.