Illustrated Glossary of Organic Chemistry

Saturated: (1) A molecule that has no pi bonds. Often refers to carbon-carbon pi bonds, but can also include other pi bonds as well.




Cyclohexene

Cyclohexane
Catalytic hydrogenation with molecular hydrogen (H2) and Pt (a catalyst) convert cyclohexene (an unsaturated molecule because it has one pi bond) into a cyclohexane (a saturated molecule which lacks a pi bond).

(2) A solution which contains the maximum amount of solute. No more of the solute can be dissolved in the solution.




All of the NaCl (the solute) has dissolved in the water.
This solution is not saturated.
  
Some NaCl remains undissolved (white solid at the bottom).
More NaCl cannot be dissolved. This solution is saturated.