Question

Glucose molecule reacts with X number of molecules of phenyl hydrazine to yield osazone. The value of X is:

Answer 1

Glucose first reacts with phenyl hydrazine giving phenylhydrazone. Then the adjacent $—CHOH$ group is oxidized by a $2^{nd}$ phenyl hydrazine molecule and itself is reduced to aniline. The resulting carbonyl group reacts with $3^{rd}$ phenyl hydrazine molecule giving osazone.