The required apparatus (see Figure 1
) contains a capillary metering valve, A,
followed by a flowmeter, B,
to control and monitor the flow of nitrogen through the system. Halogenated vinyl plastic tubing*
and a rubber fitting, C,
are used to connect the flowmeter to a sidearm of a reaction flask, D.
is a 250-mL round-bottom, boiling flask, resting in a suitable heating mantle, E.
is provided with a 225-mm Hopkins coil reflux condenser, F.
The condenser terminates in a U-shaped trap, G,
which contains two 25-g bands of 20-mesh zinc, the bands being bounded and separated by three 3-inch plugs of glass wool. The trap terminates in an adapter, H,
that by means of a halogenated vinyl plastic tubing and a twistcock connector, I,
connects with a 250-mL gas washing bottle, J.
The inlet (bubbling) tube extends almost to the bottom of the gas washing bottle, and it terminates in a fritted disk having a coarse porosity. The size of all glass joints is 24
, except for the 45
joint of the gas washing bottle.