Apparatus

Depending upon the type of reaction to be carried out, one of the assemblies shown, may be used, with additional modifications for inert gas inlet and outlet. You should consider very carefully what is required: heating or cooling, magnetic or mechanical stirring, temperature measurement, etc. The gas inlet can be either directly into the reaction flask or into the inlet arm of the gas 'bubbler' - it depends on the number of 'necks' available on the reaction flask.

Drying glassware
All equipment to be used should be dried (e.g. in an oven overnight at 125°C do not forget to remove all plastic or Teflon^® components before placing the glassware in the oven). After drying, the apparatus should be greased, assembled hot, using heat-resistant gloves as protection, and allowed to cool with the inert gas flowing rapidly through it. Once cool, the water connections for the condenser should be fitted - screw-on water connectors are most useful in this context.

Addition of chemicals
Chemicals should be added to the reaction flask using a pressureequalizing dropping funnel. Liquids and solid compounds are best added as solutions in the solvent used in the reaction. If the solid is insoluble, a little solvent should be added to the reaction flask, the 'bubbler' outlet sealed, a stopper to the flask opened and the gas flow rate increased. The solid can then be added from a wide-stemmed filter funnel, protected by the inert gas and solvent vapour, so that air does not enter the apparatus. Then, simultaneously unseal the 'bubbler' and restopper the flask, and then turn down the gas flow. Alternatively a solids addition tube (Errington, 1997, Harwood, et al., 2000, Furniss, et al., 1989) can be used.