Orthonitrate ion

The sodium salt of the unfamiliar orthonitrate ion (NO ) has been prepared. What hybridization is expected on the nitrogen atom at the center of this ion Predict the geometry of the N04 ion. 

Unlike the stable orthophosphate ion, the orthonitrate ion is easily destroyed it readily reacts with the water and carbon dioxide present in air to yield the nitrate ion ... 

AH° was found to be 27 kcal. and AS was 27 e.u. The large size of the constant compared with the known dissociation of pure sodium carbonate to sodium oxide and carbon dioxide suggests that NO4"3, or orthonitrate is probably formed when oxide ion is placed into fused nitrates. It may well be that the dissociation reaction for pure nitrate should be written ... 

Dr. Duke All of these equilibrium constants involving oxide ion, such as a carbonate going to oxide ion in the nitrates, are much too large. I believe that we are getting orthonitrate here and would like to have some comments on that. 

Orthonitric acid is still unknown, but its salts Na3N04 and K3NCL have been characterized by X-ray crystallography. The NO4- ion has regular Td symmetry, and its bonding can be represented by resonance structures ... 

The reaction of NaN03 with Na20 at 570 K leads to the formation of Na3N04 (sodium orthonitrate), and K3NO4 may be prepared similarly. X-ray diffraction data confirm that the [N04] ion is tetrahedral with N—O bond lengths of 139 pm, consistent with single bond character. 

The ion LV, whose calculated structure is shown in Fig. 5.11, is an anion of the orthonitric acid H3NO4 the existence of which in sufficiently concentrated solution of HNO3 has been proven. 

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