What is Dinitrogen tetroxide?
{{chembox | Name = Dinitrogen tetroxide | ImageFileL1 = Dinitrogen tetroxide.svg | ImageNameL1 = Full structural formula | ImageFileR1 = Dinitrogen-tetroxide-3D-vdW.png | ImageNameR1 = Space-filling model | ImageFile2 = Nitrogen dioxide at different temperatures.jpg | ImageSize2 = 160 | ImageName2 = Nitrogen dioxide at different temperatures | IUPACName = Dinitrogen tetraoxide | OtherNames = Dinitrogen(II) oxide(-I) | Section1 = {{Chembox Identifiers | ChemSpiderID = 23681 | InChI = 1/N2O4/c3-1(4)2(5)6 | ChEBI = 29803 | SMILES = [O-] [N+](=O)[N+]([O-])=O | InChIKey = WFPZPJSADLPSON-UHFFFAOYAS | StdInChI = 1S/N2O4/c3-1(4)2(5)6 | StdInChIKey = WFPZPJSADLPSON-UHFFFAOYSA-N | CASNo = 10544-72-6 | PubChem = 25352 | EINECS = 234-126-4 | UNNumber = 1067 | RTECS = QW9800000 }} | Section2 = {{Chembox Properties | Formula = N<sub>2</sub>O<sub>4</sub> | MolarMass = 92.011 g/mol | Appearance = colourless liquid / orange gas | Density = 1.44246 g/cm<sup>3</sup> (liquid, 21&nbsp;°C) | Solubility = reacts | MeltingPtC = −11.2 | BoilingPtC = 21.69 | VaporPressure = 96 kPa (20 °C)<ref>[http://www.itcilo.it/english/actrav/telearn/osh/ic/10102440.htm ''International Chemical Safety Card'']</ref> | RefractIndex = 1.00112 }} | Section3 = {{Chembox Structure | MolShape = planar, ''D''<sub>2h</sub> | Dipole = zero }} | Section4 = {{Chembox Thermochemistry | DeltaHf = +9.16 kJ/mol<ref name=Atkins>P.W. Atkins and J. de Paula, ''Physical Chemistry'' (8th ed., W.H. Freeman, 2006) p.999</ref> | Entropy = 304.29 J&thinsp;K<sup>−1</sup>&thinsp;mol<sup>−1</sup><ref name=Atkins/> }} | Section7 = {{Chembox Hazards | ExternalMSDS = [http://encyclopedia.airliquide.com/sds/en/090_AL_EN.pdf External MSDS] | EUIndex = 007-002-00-0 | EUClass = Very toxic ('''T+''')<br />Corrosive ('''C''') | RPhrases = {{R26}}, {{R34}} | SPhrases = {{S1/2}}, {{S9}}, {{S26}}, {{S28}}, {{S36/37/39}}, {{S45}} | NFPA-H = 3 | NFPA-F = 0 | NFPA-R = 0 | NFPA-O = OX | FlashPt = Non-flammable | LD50 = |