Question

Give reason why particles of sugar dissolve in water but not in oil.

Answer 1

For a liquid to dissolve a solid, the molecules of the liquid and solid must attract one another.

The bond between the oxygen and hydrogen atoms (O–H bond) in sugar (sucrose) gives the oxygen a slight negative charge and the hydrogen a slight positive charge. Therefore sucrose is a polar molecule.

The polar water molecules attract the negative and positive areas on the polar sucrose molecules which makes sucrose dissolve in water.

A non-polar substance like oil does not dissolve a polar substance like sucrose.

Hence sugar does not dissolve in oil.