GROUPV 211
Connections to induction coil
Conical flask
Platinum wire electrodes
Figure 9.1
monoxide, NO. The combination caused by an electric discharge
can readily be shown in the laboratory using the simple apparatus
shown in Figure 9.1.
PHOSPHORUS
White phosphorus is very reactive. It has an appreciable vapour
pressure at room temperature and inflames in dry air at about
320 K or at even lower temperatures if finely divided. In air at room
temperature it emits a faint green light called phosphorescence; the
reaction occurring is a complex oxidation process, but this happens
only at certain partial pressures of oxygen. It is necessary, therefore,
to store white phosphorus under water, unlike the less reactive red
and black allotropes which do not react with air at room tempera-
ture. Both red and black phosphorus burn to form oxides when
heated in air, the red form igniting at temperatures exceeding 600 K,
