JOURNAL OF CHEMICAL EDUCATION
0
TRANSFER TUBES AND TUBE OPENER GERALD W . A. FOWLES and CHARLES M. PLEASS
The University, Southampton, England
THEintroduction into a reaction vessel of volatile and filled together. The small tubes, which are made substances which are affected by moisture, e.g., SiCl,, TiCL, VCla, is often carried out in vaeuo by magnetically breaking a very thin-walled bulb containing the substance. The following modification of this technique has been found to be more satisfactory. We have used the sturdier and more easily made storage tubes illustrated in part a of the figure. Only one is shown; several may be connected to a manifold
ninefer Tub.
( a ) and Breaker
V-d
(6)
from 3 4 mm. diameter Pyrex tubing, have two constrictions, one (A) with thick walls for subsequent sealing under vaeuo. The tubes are evacuated, flamed out, filled, and sealed off at A in the usual way. When the substance is required for a reaction, a tube is scratched with a file a t the constriction B, and placed in the breaker apparatus (part b of the Figure) with the breaker K resting on the constriction. There is little danger of the sealed tnbe breaking during the usual preliminary flaming out under vacuum since its walls are of normal thickness. The breaker is filled with lead shot rather than soft iron, so that instead of lifting the breaker with a strong magnet, the breaker apparatus is inverted by twisting slowly about the ground joint M when the breaker slides gently away from the sealed tube. A second, more rapid twist about M returns the apparatus to the vertical position and causes the breaker to drop sharply onto the scratched constriction and snap the tube into two parts. A small amount of glass wool, N, absorbs the impact of the breaker on the bottom of the breaker vessel. The breaker vessel is pushed in, in two or three places (P) near ground joint M, since otherwise the one portion of the sample tnbe is liable to be forced into the ground joint, and very effectively prevent the volatile substance from being distilled away from the breaker vessel.
