Microscale Gas Chemistry:

Limewater is a clear colorless saturated Ca(OH)2(aq) prepared by mixing 1.5 g Ca(OH)2(s) per liter of water.  Stir or shake vigorously and allow the solid to settle overnight.  When using limewater, decant carefully to avoid transferring any solid or suspended Ca(OH)2(s).  In the following picture, limwater is stored in a 1-L plastic water or soft drink bottle.  A syringe is used to apply pressure in controlled increments, say 5-mL at a time.  The limewater used in this device is carefully decanted from  a 2.5-L acid bottle where it is prepared.  The contents of this simple dispenser remain clear for long periods of time.  Replace the rubber stopper with the original bottle cap for long-term storage.