Sciencemadness Discussion Board

Ammonium nitrate and hydrochloric acid ???

D2DT - 3-7-2016 at 23:17

Hi,
I added some ammonium nitrate to some HCl and the ammonium nitrate bubbled for some time with the solution turning a light yellow colour, with some crystals still on the bottom of the container. Would this form nitric acid with ammonium chloride or what could this solution be?
thanks

Tsjerk - 3-7-2016 at 23:36

Have a look at NOCl, it forms with chloride in HNO3

woelen - 4-7-2016 at 00:17

The bubbles most likely are a mix of Cl2 and ONCl. The light yellow color is due to dissolved ONCl in hydrochloric acid. This yellow/orange gas dissolves very well in concentrated hydrochloric acid and is stable in such concentrated acid. When the concentration is reduced, then ONCl hydrolyzes (reacts with water) to HNO2 and HCl.

Making HNO3 from NH4NO3 and conc. HCl hardly is possible. You get many byproducts and isolating the HNO3 from the mix is impossible. What you get is what best can be called "poor man's aqua regia".

D2DT - 5-7-2016 at 17:55

Thanks for the responses this helps alot :)

CRUSTY - 13-7-2016 at 11:43

Quote: Originally posted by woelen  

Making HNO3 from NH4NO3 and conc. HCl hardly is possible. You get many byproducts and isolating the HNO3 from the mix is impossible. What you get is what best can be called "poor man's aqua regia".


Couldn't this be used to form a sort of in situ nitric acid since you've got a proton donor and nitrate ions? Copper metal reacts with a solution of conc. HCl and KNO3 as it would nitric acid, so I'd expect a solution of NH4NO3 and HCl to behave similarly.

woelen - 14-7-2016 at 00:04

Yes, you form in situ nitric acid, but this is mixed with the hydrochloric acid, so you always get properties similar to aqua regia.

PHILOU Zrealone - 14-7-2016 at 11:48

NH4NO3 + HCl <=H2O=> NH4Cl + HNO3
So the 4 molecules are present into the mix...as discretely explained by Woelen ;)

vmelkon - 14-7-2016 at 12:00

I recommend adding H2SO4 solution if you want to make a poor man's nitric acid solution.

unionised - 14-7-2016 at 12:17

I agree- by using H2SO4 you avoid any risk of chlorides of nitrogen and also "losing" oxidising power by reaction with NH4 ions.