I'm trying to make nitric acid. The "classic" nitrate salt+HCl+Cu process.

A friend gave me the nitrate in fertilizer form and neither of us even had a clue if it contained nitrates, however I tried making a small batch to see if it works. It didn't generate any visible NO2 gas. At least there didn't seem to be any orange/red-ish fumes in and around the bottle.
Hoooowever gas was being generated (colourless) and the Cu was being eaten up. After some time the solution started turning dark green. A while after that, clumps of a percipitant started forming in the solution. Seemed to be white, but slightly green because of the color of the solution.
I took the clumps out since they started blocking the gas from leaving the bottle and checked if they could be dissolved in water. As expected, they dissolved. I dipped in some Al metal and saw that a brownish powder started forming on it's surface. I'm assuming the powder was Cu and the Al was replacing it in the solution.

I've no clue why I managed to dissolve copper, but seemingly no NO2 gas was formed.
Does anyone have an explanation for this? Also, any idea how I could actually produce nitric acid from the fertilizer that I have or should i just buy some KNO3?

Buy some KNO3 and sulfuric acid and make the HNO3

 

Balanced equation: H2SO4 + 2KNO3 ---> K2SO4 + 2HNO3

Edited July 9, 20196 yr by ScoobeeDoobee