Preparation and Reactions
Nitrogen dioxide typically arises via the oxidation of nitric oxide by oxygen in air:
- 2 NO + O2 → 2 NO2
In the laboratory, NO2 can be prepared in a two step procedure by thermal decomposition of dinitrogen pentoxide, which is obtained by dehydration of nitric acid:
- 2 HNO3 → N2O5 + H2O
- 2 N2O5 → 4 NO2 + O2
The thermal decomposition of some metal nitrates also affords NO2:
- 2 Pb(NO3)2 → 2 PbO + 4 NO2 + O2
Alternatively, reduction of concentrated nitric acid by metal (such as copper).
- 4 HNO3 + Cu → Cu(NO3)2 + 2 NO2 +2 H2O
Or finally by adding concentrated nitric acid over tin. Stannic acid is produced as byproduct.
- 4HNO3 + Sn → H2O + H2SnO3 + 4 NO2
Read more about this topic: Nitrogen Dioxide
Famous quotes containing the words preparation and, preparation and/or reactions:
“It’s sad but true that if you focus your attention on housework and meal preparation and diapers, raising children does start to look like drudgery pretty quickly. On the other hand, if you see yourself as nothing less than your child’s nurturer, role model, teacher, spiritual guide, and mentor, your days take on a very different cast.”
—Joyce Maynard (20th century)
“With memory set smarting like a reopened wound, a man’s past is not simply a dead history, an outworn preparation of the present: it is not a repented error shaken loose from the life: it is a still quivering part of himself, bringing shudders and bitter flavours and the tinglings of a merited shame.”
—George Eliot [Mary Ann (or Marian)
“We have all had the experience of finding that our reactions and perhaps even our deeds have denied beliefs we thought were ours.”
—James Baldwin (1924–1987)