Funnel, short-stem

Kurzstieltricliter short-stem funnel, short-stemmed funnel kurzkettig short-chain kurzschlieBen short-circuit Kurzschluss... 

If the crude substance contains an insoluble impurity, difficulty may be experienced at a later stage in estimating how much solute has crystallised from the cold solution. The hot solution should therefore be filtered into another tube through a very small fiuted filter paper contained in a small short-stemmed funnel. The solution must always be clear before cooling is attempted. 

Sodium salt of eosin. Grind together in a mortar 12 g. of eosin with 2 g. of anhydrous sodium carbonate. Transfer the mixture to a 250 ml. conical flask, moisten it with 10 ml. of rectified spirit, add 10 ml. of water and warm on a water bath, with stirring, until the evolution of carbon dioxide ceases. Add 50 ml. of ethyl alcohol, heat to boiling, and filter the hot solution through a fluted filter paper (supported in a short-stemmed funnel) into a beaker, and allow to stand overnight. Filter ofiF the browiiish-red crystals of sodium eosin, wash with a little alcohol, and dry. The yield is 10 g. 

For purification, it is dissolved in 9-9.5 1. of boiling benzene (Note 4). The solution is filtered rapidly, using a 32-cm. folded filter in an 8-in. short-stem glass funnel. The recovery is 59-70 g. The fine, white crystals, which melt at 169-170° (Note 5), are stored in a brown glass bottle under nitrogen (Notes 6, 7, 8). 

If a reagent of adequate purity for a particular determination is not available, then the purest available product must be purified this is most commonly done by recrystallisation from water. A known weight of the solid is dissolved in a volume of water sufficient to give a saturated or nearly saturated solution at the boiling point a beaker, conical flask or porcelain dish may be used. The hot solution is filtered through a fluted filter paper placed in a short-stemmed funnel, and the filtrate collected in a beaker this process will remove insoluble... 

Get yourself a stemless funnel, or, at least, a short-stemmed funnel. Why Go ahead and use a stem funnel and watch the crystals come out in the stem as the solution cools, blocking up the funnel (Fig. 43). 

Funnels, 2 of smallest size, one each of other sizes up to 12 cm. Cylindrical Buchner funnel, about 8 cm. Dropping funnel, 25 c.c. capacity with short stem and 100 c.c. capacity with long stem. 

A short stem, flame-polished funnel of diameter ca. 12.5 cm, free of any scratches or broken edges, was used to prevent spontaneous decomposition of diazomethane. 

F. 100-ml separatory funnel with short stem, to serve as separator of NG from the spent acid... 

The ligroin solution of the chloramine is separated from the aqueous layer in a chilled, short-stemmed 1-1. separatory funnel and washed successively with 50 ml. of ice-cold 3 N sodium hydroxide (Note 7), 50 ml. of ice water, and 50 ml. of cold 2 N... 

The sulfuric acid layers are transferred directly into the 500-ml. short-stemmed separatory funnel to be used in the next step. The solution, which usually has a light brown color, should be cold and well mixed before the ring-closure operation. The ratio of acid to water is important, and only the amounts specified should be used. 

Filtration of Hot Solution (see also Filtration).—This operation is usually necessary in order to remove insoluble impurities, filter fibres, etc. When the substance does not separate rapidly from the hot solution, and the liquid filters quickly, the solution may be filtered through an ordinary funnel with a short stem, fitted with a folded filter paper (Pig. 1). Both funnel and paper should previously be warmed in a steam bath. Or, the solution may be filtered with suction, using suitable types of apparatus (Pigs. 27,28). The funnel and filtering medium should be previously warmed. When the filtrate is collected in a thick glass suction flask,... 

The neck of the flask can be partially closed with a loose-fitting, short-stemmed, glass funnel. On further heating the dark-coloured mass grows lighter until finally it is colourless, or only a faint straw colour. 

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