Question

Glucose or sucrose are soluble in water but cyclohexane or benzene (simple six membered ring compounds) are insoluble in water. Explain.

Answer 1

“Like dissolves like” is the concept for the solubility. That means polar molecules dissolve in polar solvents and non-polar molecules dissolve in non-polar solvents.

If a molecule forms $H$-bond with water then that molecule will also be soluble in water because there exists $H$-bonds in water as well(similar intermolecular force).

Glucose has $5-OH$ groups and sucrose has $8-OH$ groups and both can form $H$-bond with water molecules.

This is the reason why glucose and sucrose are soluble in water.

But in case of benzene and cyclohexane both are non-polar in nature and they cannot form $H$-bond with water. So, they are insoluble in water.