1) Structure under different conditions

Required: 2 % fructose solution; NaOH-solution (0,1-M) ; Glucotest-strips; test-tube and -holder; Bunsen burner

Fill two test-tubes with each 2 ml of fructose solution. Add to one of them 5 drops of NaOH-solution.
Bring to boil for a short moment and check each one with Glucotest-strips .

Observations? - Conclusions?


2) Fructose and Fehling's Test

Repeat experiment 1) but use instead of Glucotest-strips the Fehling's test

Observations? - Result?


3) Detection of fructose

Required: 2 % fructose-solution; alc. solution of resorcin (1%) ; conc. HCl; t.t., -holder; BB

Give 2 ml of fructose-solution into a test-tube. Add 1 ml of conc. HCl and a few drops of resorcin-solution. Heat unti1 boiling (not too long) .
Evtl. repeat with glucose-solution.

Observations? - Result?