why is glucose soluble in water when it is known that organic compounds dissolve only in non polar solvents?

Answer 1

Your generalization is not true. Polar molecules will dissolve in polar solvents, non-polar will usually not. Sugar molecules are polar, as are alcohol molecules. Fat and oil molecules are non-polar, so they won't dissolve in a polar substance like water. It is true that most organic compounds are non-polar, but not all. On the other hand, since polar molecules like alcohol also have a non-polar end, they can dissolve some non-polar substances.

Answer 2

True, the rule of "thumb" is "like dissolves like" i.e. polar dissolves polar, and non polar dissolves non polar. However, u may have heard (or not heard) the saying that water is the "universal solvent". This is because water is covalently bonded (non polar) but it has a positive and negative end region (polar). This makes it an attractive solvent to both polar (like salt) and non polar (like sugar). If drawn correctly, the water molecule looks a little like a "micky mouse ballon". The ears are the little hydrogens attached to the face ( the much larger oxygen).
The electrons are shared, but in the region where they connect. The "ears" (hydrogen) are now mostly just the hydrogen protons, making the "top" positive. Oxygen (the face) now has two more electrons being shared with it, making the "chin" side more negative.

Answer 3

It is not always true that polar molecules will be soluble in polar solvents only and not in the non polar one. And similarly with non polar molecules.
For glucose in the water it do exists in two isomeric forms one of which has open chain and is able to form hydrogen bonds with water molecules which cause for their solubility in water.
Also vitamin c which is citric acid though organic but soluble in both the water and non polar solvents too.

Answer 4

Obviously, it is NOT known that (all) organic compounds dissolve only in non polar solvents. I dimly remember my chemistry teacher saying something about some organics being polar.

Answer 5

They really want you think, what they are thinking about the situation.... But i dont know what u mean really.. grr..