Laboratory Methods of Organic Chemistry - Sciencemadness Dot Org

CHAPTBK V
ALDEHYDES
1. FORMALDEHYDE
THE side tube (length about 10 cm.) of a distilling flask (capacity
250 c.c.) is bent upwards at the junction with the neck of the flask.
The end of the side tube, drawn out into a capillary (internal diameter
1-0-1-5 mm.), is then inserted through a cork into a piece of
combustion tubing about 30 cm. long (Fig. 53). Within the tubing
FIG. 53
and about 6 cm. from the point of the capillary is a copper spiral
4 cm. long. The tubing slopes upwards at a small angle and its
upper end is connected with a vertical condenser, preferably of the
coil type. To the lower end of the condenser there are attached two
communicating receivers which, during the experiment, are almost
completely immersed in a freezing mixture. The short side tube of
the second receiver is connected to the pump. Into the distilling
1 Tollens, Ber., 1886, 19, 2133. The explanatory remarks on the preparations
1-3 are collected along with the experiments on p. 210 et seq.
203