Re: How can a complex sugar be distinguished from a simple one?

This sounds like a homework - type question. Nevertheless, I will try to 
provide some hints.

I am not so sure what's a Trommer's test. I would assume that it's some 
kind of Fischer's test (reducing vs nonreducing).


Saccharine is not a sugar at all. (Obvious difference from the rest).
Starch is a polysaccharide, and gives a reaction with iodine. Fischer's 
test produces none or very little color with starch.
Maltose is 1->4 diglucopyranoside with one reducing end.
Lactose is 1->4 glucogalactopyranoside with the reducing glucose.
Glucose, well, I hope you know what it is.

If Trommer's test isn't the same as Fischer's test, it also may be the 
color reaction with diphenylamine and aniline, in presence of H2SO4. 
Products are usually identified by color. Since I am not webified right 
now, I cannot research what colors do individual sugars produce, 
but this must be in a textbook somwhere, to be sure.

If you can clarify (in an email, perhaps) what is Trommer's test, I 
may be able to help you further.