It is my understanding that the addition of small quantities of urea to concentrated RFNA forms nitric acid, oxides of carbon, and water, rather than
urea nitrate. (If this is not the whole picture, I'd welcome any comments from the community). This got me thinking.
Suppose one creates RFNA from distilling NaNO3 and H2SO4. The addition of urea would slightly reduce the quantity of
dissolved NOx while adding water to dilute the RFNA. If the receiving flask is heated, the water would be removed along with a small amount
of nitric acid. Heating would also decompose some of the HNO3 back into water and dissolved NOx. Would slow and steady periodic
addition of urea produce a constant stream of azeotropic nitric acid? Or am I missing something really obvious?barley81 - 10-4-2012 at 14:40
Pure nitric acid boils at a lower temperature than water and the azeotrope. I think that if you heat slightly wet nitric acid, the water won't boil
off first.
[Edited on 10-4-2012 by barley81]Bot0nist - 10-4-2012 at 15:58
Pure nitric acid boils at a lower temperature than water and the azeotrope. I think that if you heat slightly wet nitric acid, the water won't boil
off first.
[Edited on 10-4-2012 by barley81]
I believe this is correct. If it wasn't, people would be concentrating nitric like they do sulfuric.
