physical properties:
odour:
colour:
aspect:
reaction with litmus paper:
chemical properties:
biuret's test
no violet colour
the solution is not protein
molish's test
violet ring spread by shaking
general test for carbohyrate. the solution react with sulphuric acid will form furfural.and then react with alpha napthol will form violet ring.
iodine's test
deep blue black
absorption of iodine to the surface of the solution
confirmatory test
fehling's test
no red red colour or ppt form
the solution is not reducing sugar
acid hydrolysis starch
time: 2 5 10 15 20
iodine:deep blue bluish violet reddish brownish yellow yellow
fehling: no red slight red distinct red marked red greater red
comment: soluble starch amylodextrin erythrodextrin achrodextrin maltose
or glucose
conclusion:
the solution is starch.
