Ascorbic acid possesses following important physico-chemical properties:

a)  It  is a white crystalline  substance.

b)  It  is freely soluble in water.

c)  Solution of the vitamin tastes sour.

d)  In  dry condition  it is stable in air and light.

e)  It  is fairly stable in cold acid solution.

f)  In an aqueous medium, particularly alkaline, it is easily oxidized on exposure to heat, light and traces of metals such as copper or silver.

g)  It  is easily destroyed during cooking.

h)  The compound  is a powerful  reducing agent and can  reduce fehling's solution. This is due to the presence of en01 group (carbons 2 and 3) in  its structure. (You have already learnt about the enol group in the carbohydrate Unit  I).

i)  Vitamin  C  also reduces  2,  6-dichlorophenolindophenol  to a colourless  leuco compound. This reaction  is very commonly utilized  for chemical  estimation of the vitamin.