acetic acid
(CH3COOH); carbohydrate exception; same gen formula
rhamnose
C6H12O5; carbohydrate. diff formula
sucrose
common; present in homes
lactose
milk
monosaccharides
glucose, fructose, ribose.
sucrose(hydrolysis)
glucose+fructose
maltose(hydrolysis)
glucose+glucose
polysaccharides
starch, cellulose, glycogen, gums, etc.
non sugars
polysaccharrides, not sweet
fact about monosaccharides
reducing
condition for reucing sugar: disac
free aldehydic or ketonic group; maltose or lactose
non reducing disac
sucrose
prep of glucose (i)
from sucrose; boiling; h2so4 or dil HCl; gives glucose+fructose
commercial method
obtained by hydrolysis of starch OR cellulose by boiling it with dilute H2SO4 at 393 K under pressure 2-3 atm.
aldohexose
dextrose; glucose
structure; heating
On prolonged heating with HI, it forms n-hexane, suggesting that all the six carbon atoms are linked in a straight chain.
Cyclic Structure of Glucose
Schiffs test; NaHSO3
cyclic structure
The pentaacetate of glucose does not react with hydroxylamine indicating the absence of free —CHO group.
alpha glucose
The α-form of glucose (m.p. 419 K) is obtained by crystallisation from concentrated solution of glucose at 303 K
beta glucose
(m.p. 423 K) is obtained by crystallisation from hot and saturated aqueous solution at 371 K.