Question

distinguish between glucose and fructose by chemical test

Answer 1

FURFURAL TEST:- The sugar is treated with an alcoholic solution of alpha-naphthol and concentrated HCl and the mixture is boiled. An immediate violet colour is produced with fructose. Whereas, the colour appears after a few minutes with glucose. 
Ammonium Molybdate test- Freshly prepared 4% aqueous solution of ammonium molybdate is added to an equal volume of 1% solution of sugar in a boiling tube, followed by 4-5 drops of glacial acetic acid. As the boiling tube is heated, fructose gives a greenish-blue coloration within 3-4 minutes whereas, glucose gives only a very faint coloration after 10 minutes. 

Answer 2

Seliwanoff's Test- Take 3 ml of the unknown sample,add Seliwanoff's Reagent to the test tube & heat it. If it is fructose then a deep cherry (red) color will be formed. If glucose a faint pink color will be formed.

Hope it helps:)