Accepted data for the Venusian atmosphere record a surface pressure of 9200 kPa and an atmospheric composition of 3.5% Nitrogen by volume. (NASA data). Using Dalton's Law of Partial Pressure this means that the partial pressure of N2 is 322 kPa and therefore Venus has 4 times as much nitrogen gas as Earth does.
If Venus possessed a CO2 free, nitrogen only atmosphere, then the boiling point of water on Venus would be 136 deg C.
Where does all the nitrogen on Venus come from and how long has the planet had this much nitrogen gas?
Huseyin,
Thank you for the reference to the work of R.D. Wordsworth.
A general search made for planetary atmospheric data produced this popular link to a 30Jun12 posting by Gary Johnson Atmosphere Models for Earth, Mars, and Titan.
http://exrocketman.blogspot.com/2012/06/atmosphere-models-for-earth-mars-and.html
The source data link kindly supplied by Mr Johnson is:-
Justus, C.G. and Braun, R.D., 2007 Atmospheric Environments for Entry, Descent, and Landing (EDL) NASA Technical Reports Server, 5th International Planetary Probes Workshop and Short Course; 23-29 Jun. 2007; Bordeaux; France.
https://ntrs.nasa.gov/search.jsp?R=20070032693
The Justus and Braun (2007) report includes model data for the Venus Environment (Section 3).
This work by Ian Miller provides a valid chemical mechanism by which nitrogen can be incorporated into the solid particles which form the process of planetary accretion :-
"There is, however, a further mechanism for accreting nitrogen. If the stellar nebula reaches the 2000 K, at that temperature nitrogen reacts with most metals to form nitrides, which, being solids, will be able to accrete, and will subsequently react hydrothermally to form ammonia able to be released during degassing."
Miller, Ian, Early Martian Atmosphere and Biogenesis (April 2001). Chemistry Preprint Archive Vol. 2001, Issue 4, pp 126-140. Available at SSRN: https://ssrn.com/abstract=2969550