Direction (Q. Nos. 15-18) This sectionis based on statement I and Stat...
The correct answer is Option A.
Racemic mixture is an equimolecular mixture of enantiomeric pairs. The rotation caused by the molecules of one enantiomer is cancelled by the rotation caused by the molecules of another enantiomer.
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Direction (Q. Nos. 15-18) This sectionis based on statement I and Stat...
Statement I: A racemic mixture is optically inactive.
Statement II: Racemic mixture contains a pair of enantiomers.
Explanation:
Racemic Mixture:
- A racemic mixture is a mixture that contains equal amounts of two enantiomers (mirror-image isomers) of a chiral compound.
- In other words, a racemic mixture is a 50:50 mixture of two enantiomers.
Optical Activity:
- Optical activity is the ability of a substance to rotate the plane of polarized light.
- A substance is optically active if it rotates the plane of polarized light, and optically inactive if it does not rotate the plane of polarized light.
Enantiomers:
- Enantiomers are mirror-image isomers that are non-superimposable on each other.
- They have the same physical and chemical properties, except for their interaction with plane-polarized light.
Explanation of Statement I:
- A racemic mixture is optically inactive because it contains equal amounts of two enantiomers.
- When a racemic mixture is exposed to plane-polarized light, the rotation caused by one enantiomer is canceled out by the rotation caused by the other enantiomer.
- As a result, the overall rotation of the plane-polarized light is zero, making the racemic mixture optically inactive.
Explanation of Statement II:
- Racemic mixture contains a pair of enantiomers.
- Enantiomers are mirror-image isomers of each other, which means they have the same physical and chemical properties, except for their interaction with plane-polarized light.
- In a racemic mixture, the enantiomers are present in equal amounts, resulting in optical inactivity.
Conclusion:
- Both Statement I and Statement II are correct.
- Statement II is the correct explanation of Statement I.
- A racemic mixture is optically inactive because it contains a pair of enantiomers in equal amounts, canceling out their individual rotations on plane-polarized light.
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