Question

why glucose and fructose
give same

Answer 1

If we obsereve the structural formulas of both glucose and fructose ,we see that they differ in their structures in#C_1 and C_2#. When they are reacted with phenyl hyrazine these two C-atoms do get involved in the reaction as shown in the above equations and thus stuctural difference disappears with the formation of same osazone as the structures from#C_3 " to "C_6 #being same in both the structures.

Answer 2

Hay everybody here is your answer. Glucose and fructose differ only in the configurations of first and second carbon atoms remaining positions are similar. So they form same osazone. Upon hydrolysis, the products glucose and fructose form needle shaped crystals.