JULY,1952
THE 4 IN 1 CHEM-MIXER RAY WENDLAND North Dakota State Ccllege, Fargo, North Dakota
THEthree-neck flask is a very valuable unit in the apparatus kit of the organic chemist. It is however not a low cost item when provided with the desired standard taper joints' and if a half dozen or so are necessary for a variety of processes, the investment is considerable. For insertion of a proper stirring device into suet a flask the neck size should he 29/42 or larger; such necks make it inconvenient to operate with a flask any smaller than 500 ml. in volume. As an added consideration one realizes that whenever a series of opere tions can be carried out in one vessel without dismantling and emptying, the experimenter can save much valuable time. The result of these deliberations led to the design and construction of the apparatus shown which I choose to call the "4 in 1 Chem-Mixer." Attached t o 'the figure is a description of items involved in its construction. By use of the "Chem-Mixer" one may rely principally on one-necked flasks of any size all of which can be adapted to fit the new device. The unit is most conveniently employed when fastened in place with the customary stirrer, dropping funnel, and reflux condenser likewise in position. Thereupon the side tube (2) is atttached to a takeoff and condenser, but the large stopcock (3) is closed for reflux operation. After the main reaction has taken place the solvent or volatile products are removed by distillation with the stopcock in the open position. After these several operations (four in number: stirring, addition, reflux, and distillation) the reaction flask and its contents are removed from the unit, which is then ready to accommodate another batch of reactants without interruption. It should be noted that the vertical bearing (4) for the stirring shaft can be easily adjusted for inclusion Currenth a W m l . 3-neckflask with 29/42 . . .ioints cost $7.10. A 11330-cc. fl&k of same type $9.00.
of a mercury seal, or, by a simpler method, attachment of soft rubber tubing over the top, which in many cases gives a perfectly acceptzhle seal.
D ~ e r i p t i o nof Item.
111 29/42 atandsrrd-taper joints into which are fitted a dropping funnel a n d refiur condenser. Theae jomts are w e d full length as obtained from supplier and curved a t the bottom for attachment to the oenter tube which connects t o the reaction vessel. (2) 28/42 standard-taper male joints for eonneation to reaction vessel and t o oollection unit for distillation. (3) Vaouum-type atapoook with three holes as shown. W h e n turned 180° from the parition i n the figure any eondensate enteting the stopcock body will drain back into the flask through tube (5). (4) 5-7-mm. tube whioh acts as bearinafor stirring shaft. (51 Drain tube atteahed t o bottom of s t o ~ o o c k(3). This drains fluid oolleoting in etapoock. I t also serves t h e important purpose of strengthenlna the side a r m attachment against accidental breakage.
