Assertion: D-glucose is dextrorotatory whereas L-glucose is laevorotatory. Reason: D-compounds are always dextro and L-compounds are always laevorotatory.

Question

Assertion: D-glucose is dextrorotatory whereas L-glucose is laevorotatory. Reason: D-compounds are always dextro and L-compounds are always laevorotatory. (A) If both assertion and reason are true and reason is the correct explanation of assertion (B) If both assertion and reason are true but reason is not the correct explanation of assertion. (C) If assertion is true but reason is false (D) If both assertion and reason are false.

Tardigrade Admin · Accepted Answer

D and L have no relation with the optical rotation. Carbohydrate having D configuration may be either dextrorotatory or laevorotatory e.g., D glucose is dextrorotatory while D-fructose is laevorotatory.

Q. Assertion : $D$ -glucose is dextrorotatory whereas $L$ -glucose is laevorotatory.
Reason : $D$ -compounds are always dextro and $L$ -compounds are always laevorotatory.

If both assertion and reason are true and reason is the correct explanation of assertion

If both assertion and reason are true but reason is not the correct explanation of assertion.

If assertion is true but reason is false

If both assertion and reason are false.

$D$ and $L$ have no relation with the optical rotation. Carbohydrate having $D$ configuration may be either dextrorotatory or laevorotatory e.g., $D$ glucose is dextrorotatory while $D$ -fructose is laevorotatory.

Q. Assertion : D-glucose is dextrorotatory whereas L-glucose is laevorotatory. Reason : D-compounds are always dextro and L-compounds are always laevorotatory.