Boiling sticks

Add a boiling stick these are thin pieces of wood sold as wooden applicators , but you must be sure that nothing will be extracted from the wood into your solution. 

Add the liquid to be distilled to the distillation flask using a stemmed funnel, together with antibumping granules or boiling stick or a magnetic flea . The flask should not be more than 50% full. Reclamp the flask in position. 

Using a glass rod or boiling stick, place a small drop of liquid in the centre of one of the plates. Do... 

Transfer the mull to the centre or along the diameter of an NaCI plate, on a piece of filter paper or tissue paper to prevent scratching by the bench surface, using a small plastic spatula or a boiling stick. 

FIG. 5 Aspirator tube in use. A boiling stick may be necessary to promote even boiling. 

Prevention of Superheating—Boiling Sticks and Boiling Stones... 

Measure the volume of the dichloromethane in a dry graduated cylinder, place exactly one-fifth of the solution in a tared Erlenmeyer flask, add a wood boiling stick (easier to remove than a boiling chip), and evaporate the solution on a steam bath in a hood. The residue of crude clove oil will be used in the thin-layer chromatography analysis. From its weight, the total yield of crude clove oil can be calculated. 

Transfer the powder on the filter to a test tube, add 4 mL of ethanol, and heat the mixture to boiling (boiling stick). Not all of the material will go into solution. That which does not is the binder. Filter the mixture into a... 

Add a boiling stick and heat the mixture to boiling, at which time the aspirin should dissolve completely. If it does not, add more water. Long boiling will hydrolyze the aspirin to salicyclic acid, mp 157-159°C. Once completely dissolved the aspirin should be allowed to crystallize slowly as the solution cools to room temperature in an insulated container. Once the tube has reached room temperature it should be cooled in ice for several minutes and then the solvent removed with a Pasteur pipette. The crystals are to be washed with a few drops of ice-cold water and then scraped out onto a piece of filter paper. Squeezing the crystals between sheets of the... 

In a Pasteur pipette loosely place a very small piece of cotton followed by 2.5 g of alumina. Add to the top of the pipette 1.5 mL of styrene and collect 1 mL in a disposable 10 x 75-mm test tube. Add to the tube 50 mg of benzoyl peroxide and a thermometer and heat the tube over a hot sand bath. When the temperature reaches about 135°C polymerization begins and, since it is an exothermic process, the temperature rises. Keep the reaction under control by cautious heating. The temperature rises, perhaps to 180°C, well above the boiling point of styrene (145°C) the viscosity also increases. Pull the thermometer from the melt from time to time to form fibers when a cool fiber is found to be brittle remove the thermometer. A boiling stick can be added to the tube and the polymer allowed to cool. It can then be removed from the tube or the tube can be broken from the polymer. Should the polymer be sticky the polymerization can be completed in an oven overnight at a temperature of about 85°C. 

Safety note If, during the course of your vacuum distillation using a microburner and a boiling stick, the liquid stops boiling and appears quiescent , it is about to bump vigorously. Stop heating, allow it to cool, break the vacuum (Box 15.4), and add a new boiling stick. 

The apparatus for performing a miniscale hot filtration is shown in Figure 2.52. A small volume of the pure solvent is first placed in an Erlenmeyer flask containing a boiling stick or several boiling stones, and a short-stemmed or stemless filter funnel containing a piece of fluted filter paper is placed in the mouth of the flask. A small stick or piece of thick paper is inserted between the flask and the funnel to... 

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