- Oil bubbler
An oil bubbler is a piece of
laboratory glassware which consists of a glass bulb filled with a small amount ofsilicone oil . The inlet to the bulb is connected to aground glass joint , while the outlet is vented to the air.Oil bubblers are used to exclude air from a reaction or a system. In the former case, the oil bubbler is fitted on the
condenser of the reaction set-up. In the latter case, an oil bubbler is usually installed at the end of theinert gas manifold on aSchlenk line to prevent contamination by atmosphericoxygen andwater .The oil bubbler acts as a one-way valve - gases (hot air, evolved gases, solvent vapors) from the inlet will bubble through the oil before being vented to the atmosphere. On the other hand, if there were an underpressure in the reaction vessel (such as when heat is removed, and the gases within contract), oil is sucked into a sump to equalize the pressure, instead of air. Wherever possible, such "suck back" should be avoided by filling the reaction apparatus with inert gas because an excessively low pressure will cause oil to be sucked into the reaction vessel, contaminating it.
Mercury bubbler
Mercury bubblers are similar to oil bubblers. The high density of mercury increases the pressure of the gas flowing through the line, since more force is required for the gas to bubble through such a dense material. However, due to the mercury's toxicity, and the risk of releasing large quantities of mercury if the bubbler were to be broken or sucked back into the gas line, the use of mercury bubblers is generally discouraged. In addition, mercury can react with various chemicals, such as ammonia and acetylenes, with potentially hazardous results [http://www.jtbaker.com/msds/englishhtml/M1599.htm] . Oil bubblers are usually adequate substitutes.Fact|date=June 2007
ee also
* A
drying tube is used to exclude moisture from reactions for less demanding applicationsExternal links
*
Wikimedia Foundation. 2010.