Plz give uses of Glycerol also analytical testa of Glycerol.

USES: Glycerol is used:

(i) as a sweetening agent in confectionery , beverages and medicines being non-toxic in nature.

(ii) in the manufacturing of explosives like dynamite and cordite.

(iii) in the manufacturing of plastics and synthetic fibres and alkyd resins.

(iv) as antifreeze in automobile radiators.

(v) in the preparation of good quality of transparent soap, hand lotions, vanishing creams, shaving creams and tooth pastes.

(vi) in the manufacture of various organic compounds like formic acid, allyl alcohol, acrolein, etc.

(vii) as a lubricant in watches and clocks.

(viii) in the preparation of non-drying inks, printing inks and stamp pads inks.

(ix) as a preservative.

Analytical Tests of Glycerol

(i) Acrolein test : When glycerol is heated with potassium hydrogen sulphate a very offensive odour is produced due to formation of acrolein. Its aqueous solution restores the colour of Schiff's reagent and reduces Fehling's solution and Tollen's reagent.

(ii) Dunstan's test : A drop of phenophthalein is added to approximately 5 mL of borax solution . The pink color appears. On adding 2-3 drops of glycerol, the pink color disappears on heating and disappears on cooling again.

(iii) To an equimolar mixture of phenol and glycerol. few drops of conc. H₂SO₄ are added and heated to 130^_o C. It is then cooled by adding water. Addition of ammonium hydroxide to this solution produces red color.