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: Racemic Mixture Definition.
A racemic mixture is comprised of equal quantities of two enantiomers. Due to opposing optical activities, their net rotation is zero.
Step 2: Properties of Racemic Mixtures.
- Represented as (±).
- Exhibits no net rotation of plane-polarized light due to cancellation of optical activity.
- A single enantiomer like (+)-2-butanol is not racemic; a 50:50 mixture with its (–) enantiomer is racemic.
Step 3: Identifying the False Statement.
Racemic mixtures are optically inactive; therefore, they do not rotate plane polarized light.
Final Answer: \[ \boxed{\text{Racemic mixture causes finite rotation of plane polarized light (Incorrect)}} \]