When sodium nitrite is exposed to air, it undergoes slow degradation through photochemical processes with a half-life of 82.3 days.
Explanation:
When sodium nitrite is exposed to air, it undergoes slow degradation processes influenced by light, known as photochemical processes. These reactions occur due to the interaction between sodium nitrite and light energy from the surroundings. The term "half-life of 82.3 days" indicates the time required for half of the sodium nitrite to degrade.
This means that after 82.3 days, the amount of sodium nitrite is halved due to this photochemical degradation. This degradation can vary depending on environmental factors. The fact that it's a slower process suggests that sodium nitrite doesn't rapidly decompose when exposed to air but rather diminishes gradually.
Source:
European Chemicals Agency (ECHA)