Question

When sugar is added to water the level of water does not increase because the sugar molecules occupy the space in between the molecules of water. But if we add lots and lots of sugar in water, shouldn't the sugar molecules compress the water molecules and form a solid? But they don't? Why?

Answer 1

The interaction of the electrostatic field of an ion with water tends to align the dipolar water molecules in the direction of the field. In this way the field tends to disrupt hydrogen bonded structures in liquid water, and to compress the water molecules surrounding an ion. These electrostatic effect give rise to a shrinkage of the water.