Flask Boiling Flat Bottomed/ Round Bottomed

U–tube filled with a sodium hydroxide is used for a cleaned and dried gas. U–tube filled with a 1 mol dm^–3 aqueous potassium nitrate solution is used as a permanent salt bridge. U–tube is a device used for water electrolysis, for laboratory hydrogen and oxygen obtaining.

Capillary tubes are great for liquid measurement, liquid transfer and sample collection applications.