Modern inorganic chemistry

GROUP V 223

and is very susceptible to explosive decomposition. Hence the proper-
ties studied are those of the hydroxyammonium salts, i.e. containing
the ion NH 3 OH*, analogous to NH^. These are strong reducing
agents, for example they reduce iron(III) to iron(Il) salts in acid
solution :

4Fe3+ + 2NH 3 OH + ->4Fe2+ + N 2 O + 6H+ + H 2 O

Note that dinitrogen oxide is the other product. In alkaline solution,
however, hydroxylamine oxidises iron(II) hydroxide to iron(III)
hydroxide and is itself reduced to ammonia. This is an example of
the effect of pH change on oxidation-reduction behaviour (p. 101):

NH 2 OH + 2Fe(OH) 2 + H 2 O -> 2Fe(OH) 3 + NH 3

Hydroxylamine condenses with the carbonyl group of an aldehyde
or ketone to form an oxime :

NHOH

H 20

Hydrazine, N 2 H 4

Hydrazine, like hydroxylamine, may be considered as a derivative
of ammonia, one hydrogen atom being replaced by an —NH 2 group.
The structure is shown below (Figure 9.5).

O

N

Figure 9,5

Hydrazine is prepared, anhydrous and in good yield, by glow
discharge electrolysis of liquid ammonia; a platinum cathode is
immersed in liquid and a platinum wire anode is mounted just