Here are a couple of Handy videos worth watching regarding testing nitrate fertilizer and making nitric acid. All credit for them goes to nurdrage.com and their website has more interesting info.
In this video we show you how to test if a fertilizer has nitrates rather than urea or ammonia as its nitrogen source.
The idea is quit simple, in a strongly acidic solution the nitrates will behave like nitric acid and dissolve copper metal releasing nitrogen dioxide gas. Looking for this gas is a strong indication for the presence of nitrates.
WARNING: these reactions produce toxic nitrogen dioxide gas, this must be performed outside or in a fume hood.
To perform the test, simply mix some of your fertilizer with water to dissolve the nitrates and then mix it with hydrochloric acid. Then add in some copper metal.
The reaction is very slow to start up unless you heat it. A nerdy way of heating it on the spot without using a heater is to add a small ball of aluminum metal, don't use too much or it will go out of control. Stir the mixture as the aluminum dissolves to distribute the heat evenly.
After the mixture is heated, place a glass container over the mixture to keep the gases in. If nitrogen dioxide is forming the distinctive brown nitrogen dioxide will fill the container.
And that's how you can tell if there are nitrates in your fertilizer.
If you want to test for ammonia (in case you have ammonium nitrate) just mix some fertilizer with half as much sodium hydroxide and add a little water to cover it. If it starts bubbling and releasing ammonia gas then it contains ammonia.
3 ways to make nitric acid based on two different chemical approaches both of which can be done using easily accessible materials.
Warning: The procedures in this video produce large quantities of toxic gases and deal with highly corrosive acids. All work must be performed in a fume hood with proper safety equipment. And all apparatus must be glass to withstand the acids.
Chemically, nitric acid is made by bubbling nitrogen dioxide into water. So the objective in this approach is to generate nitrogen dioxide. This can be done by reacting hydrochloric acid, a nitrate salt and copper. Around 80grams of sodium nitrate, over 30 grams of copper and 100mL of hydrochloric acid (37% 12M) are the quantities needed. The exact amount isn't critical. For usable concentrations, the amount of water being converted should be small, around 20-50mL.
Any source of nitrate is usable including potassium nitrate, ammonium nitrate and even nitrate-based fertilizers. You can use our previous video on testing for nitrates if you want to determine if yours can be used. http://www.youtube.com/watch?v=f5M3rU...
The tricky part now is leading the gas into water. Two approaches are shown in the video. In the first approach three containers, such as jars are place inside each other to force the gas to go into the water. This is very inefficient but is very simple to do.
The better approach is to lead the gas out of the generator through a tube and into a chilled container of water.
The water that's converted into nitric acid can be replaced with hydrogen peroxide for better yield.
The chemical waste that's generated contains the valuable copper used before and recovering it is worthwhile due to todays high copper prices. This is simply done by putting in enough aluminum metal that it reacts with all the acids and copper in solution to create a slurry of copper. This can be filtered to obtain a residue of copper. Its highly contaminated but can still be used to make more nitric acid.
For further information on the chemistry type "copper and nitric acid" into google. The hydrochloric acid and nitrate salt behave as nitric acid (with nitrate from the salt and protons from the hydrochloric acid) and dissolve the copper releasing nitrogen dioxide gas.
You can use other concentrations of hydrochloric acid but you need to decrease the amount of water added to keep the concentrations the same.
Finally, the last way of making pure nitric acid is to react concentrated sulfuric acid and a pure nitrate salt (NOT fertilizer) and heat it in a glass distillation apparatus to distill over the pure nitric acid. Stoichiometric quantities of both reagents are recommended for maximum yield.
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