ABSTRACT
When nitrites and nitrates are thermally decomposed, nitrogen, oxygen, and their compounds are produced. A literature survey produces the following list of substances which appear in one or another decomposition: O
, N
, NO, NO
, N
O
, N
O
, N
O
. Which of these compounds are produced in any specific case depends on the salt, temperature, and experimental conditions. Since reactions between these compounds occur quite readily, thermodynamic functions for them have been listed (Tables 5.1 to 5.8). The matter of reactions between all these compounds is somewhat complicated, because several of them are thermodynamically quite unfavorable and thus do not need to be considered. On that basis the following conclusions can be drawn:
N
O
is unstable with respect to dissociation to either N
O
or N
O
from 298 K up. The equilibrium N
O
= 2 NO
shifts markedly to the right with increasing temperature. Above 400 K the concentration of N
O
is negligible. Although N
O
has been reported as a product of nitrate decomposition, it is unstable with respect to dissociation into NO
and NO above 400 K; it could therefore exist in equilibrium mixtures only near ambient temperatures.
