90. Humin is the fraction of humus,
which is having following
properties :
(a) Highest molecular weight
w
and insoluble in both acid
and alkali
(b) Highest molecular weight
and soluble in both acid
and alkali
(c) Lowest molecular weight
and insoluble in both acid
and alkali
(d) Lowest molecular weight
and soluble in both acid
and alkali
Answers
Answer:
Abstract
Humin is the insoluble component of soil organic matter (SOM) that remains after extraction of the other components of SOM that are soluble in aqueous base. Humin usually makes up a substantial component of SOM, but its lack of solubility and intractable nature have made it difficult to study. To put this contemporary review of humin into perspective, a summary of the historical development of SOM studies and the terminology used to describe the various components of SOM is presented.
Humin: Highest in molecular weight, darkest in colour, insoluble in both acid and alkali and most resistant to microbial attack. Polymerized product of a part of the FA and HA fractions.
On the basis of resistance to degradation and of solubility in acids and alkalis, humic substances have been classified into five chemical groupings. Fulvic acid: lowest in molecular weight, lightest in colour, soluble in both acid and alkali and most susceptible to microbial attack
Fulvic acid
On the basis of resistance to degradation and of solubility in acids and alkalis, humic substances have been classified into five chemical groupings. Fulvic acid: lowest in molecular weight, lightest in colour, soluble in both acid and alkali and most susceptible to microbial attack
Answer:
(d) Lowest molecular weight and soluble in both acid and alkali.
is your right answer