470 PRACTICAL ORGANIC CHEMISTRY boat M to be introduced into the combustion tube through the end (normally sealed by a tight-fitting rubber bung J) while oxygen is flowing. The combustion tube L is made preferably of transparent silica (though hard glass can be used) and is 60 cm. long and i cm. in diameter; at the further end it has a short fine beak (2 cm long, ca. 0-25 cm. in diameter). A small square of asbestos board K, having a slit cut to fit the combustion tube, is placed up against the side-arm H to screen the rubber bung J from heat and thus avoid any possibility of its evolving volatile carbon compounds during the combustion. The combustion tube is empty, with the exception of the boat, up to the furnace mouth. The packing of the tube is considered in detail below. The furnace and thermostatic mortar. For heating the tube packing, a small electric furnace N has been found to be more satisfactory than a row of gas burners. The type used consists of a silica tube (1*5 cm. in diameter and 25
This is the end of the preview. Sign up
access the rest of the document.
This note was uploaded on 09/19/2011 for the course CHM 2211 taught by Professor Castalleano during the Fall '06 term at University of Florida.