Question

Which of the following is incorrect about racemic mixture?

• A. Racemic mixture causes finite rotation of plane polarized light
• B. It is often designated as (±)
• C. (+)-2-butanol is a racemic mixture
• D. Plane polarized light remains invariant inside a racemic mixture

Hint:

Racemic mixtures are optically inactive because the optical effects of enantiomers cancel each other.

Answer 1

The Correct Option is A

Step 1: Understanding racemic mixtures.
A racemic mixture contains equal amounts of two enantiomers (optical isomers). Their optical rotations cancel each other.
Step 2: Correct statements.
- Designated as (±).
- Plane polarized light remains unchanged because optical activities cancel.
- (+)-2-butanol alone is not racemic, but if mixed with its (–) enantiomer in equal proportion, it forms a racemic mixture.
Step 3: Identifying the incorrect option.
Since racemic mixtures are optically inactive, they do not cause finite rotation of plane polarized light.
Final Answer: \[ \boxed{\text{Racemic mixture causes finite rotation of plane polarized light (Incorrect)}} \]