1352
JOURNAL OF CHEMICAL EDUCATION
J a y , 1931
AN INEXPENSIVE WATER-COOLED CONDENSER C.E.WHITE, UNIVERSITY OP MARYLAND, COLLEGE PARK. MD.
Many elementary laboratory manuals describe air-cooled condensers in experiments illustrating the process of distillation. This is presumably done because of the apparently prohibitive cost of the water-cooled condenser. The condenser illustrated below can be assembled for about ten cents and quite efficiently illustrates the process of separating liquids of different boiling points. The price mentioned does not include the rubber tubing for water connection. Two feet of this are necessary and cost about fifteen cents. If desired, very short pieces can be used and connected to glass conveying tubes. The apparatus required includes: one foot of glass tubing 17 mm. inside diameter, two and one-half feet of glass tubing 4 mm. inside diameter, and two number two two-hole rubber stoppers. Since the stoppers must be moved a considerable distance on the condenser tube it sometimes helps if the bole of the stopper is moistened with glycerin. If desired, number one stoppers and a smaller water jacket may be chosen. The smaller the water jacket the more efficient is the condenser for the amount of water used. It may be shortened also about two inches without impairing the efficiency greatly, since about 99% of the condensation takes place in the first ten inches of the tube. In the event that water connections are not available, a siphon effect may he used.
