JEE Main levelSingle correct optionDifficulty 2 of 3bm171
Assertion (A): D-glucose does not give Schiff's test although it is an aldohexose.
Reason (R): In solution glucose exists mainly as cyclic hemiacetal forms and contains only a trace of the free aldehyde form.
ABoth A and R are true, and R is the correct explanation of A
BBoth A and R are true, but R is not the correct explanation of A
CA is true but R is false
DA is false but R is true
Answer: A
The cyclic hemiacetal (pyranose) forms have no free CHO, so very little aldehyde is available to react with Schiff's reagent. Both statements are true and R explains A.