Warning: Ammonia is a toxic gas, work outside or in a fume hood. Sodium hydroxide is corrosive, wear gloves when handling it. Greetings fellow nerds. In this video we’re going to make ammonia gas as well as ammonia solution. Ammonia, consisting of one nitrogen bonded to three hydrogen atoms, is one of the most produced chemicals in the world. Industrially, it’s made by the haber-bosch process where nitrogen is reacted directly with hydrogen over an iron catalyst. For the amatuer chemist this is a rather excessive amount of work and completely unnecessary as there are domestic sources of ammonia containing products that we can extract ammonia from. As for why an amatuer would want ammonia, there are few reasons. It’s a weak base so it’s good for neutralizing acids. Being a volatile base it can easily be boiled out of reactions when no longer needed. It’s a complexing agent for transition metals. And it can be used to make amines and other nitrogen containing chemicals. While it is possible to buy ammonia solution in the cleaning products section of a grocery store, the amateur chemist may want to make their own ammonia solution as domestically available ammonia may contain detergents and other additives which make it unsuitable for amateur use. Even if you got pure ammonia solution, domestically available sources are often not very concentrated, ranging from 5%-10%. This can be especially problematic when making hydrazine as you need very high concentrations of over 20% to ensure a good yield. Also, making ammonia gas as opposed to ammonia solution is useful for non-aqueous reactions as well as gas phase reactions. I’m actually doing these ammonia experiments so i can find a cheap and high yielding method to feed into a future project of making nitric acid by the ostwald process. Not sure when i’ll get there but i felt i should pin this step down before then. So let’s get started. I’ll let you know up front though that the only really viable method I found was to react urea and sodium hydroxide. So you can skip ahead to that part of the video. First i’m going to show all the methods that worked badly. Now i’m going to collect my ammonia in water as ammonia has very high solubility in water. This will also let me measure the effectiveness of my production methods. First I weigh the receiver flask and then add in 100mL water before weighing again to obtain an exact weight of water. As you can see the graduations on the flask are not always accurate. Now for the first attempt I’m going to try boiling the ammonia out of 600mL of household ammonia I purchased at walmart. If this works, it would provide a way of concentrating easily available household ammonia. We can’t just boil the water out as ammonia is released before water and ammonia does not form azeotropes with water. Anyway, a reflux condenser is installed on top of the flask to condense any water vapor that might boil out. A long plastic tube is connected to the top of the condenser and lead into the receiver. It’s kept above the water rather than submerged as ammonia is extremely soluble and will suck back into the generator. Now all we do is heat up the household ammonia solution until it just starts to reflux and hopefully the ammonia gas boils out and dissolves in the receiver. The receiver was submersed in cold water to improve solubility of the ammonia. Now you might be wondering why i’m trying to remake ammonia solution starting with ammonia solution. My primary objective is to make ammonia gas, dissolving it in water is a way of measuring the effectiveness. Also domestic ammonia solutions are not always pure and may contain detergents. Boiling it out like this is a means of purifying it. Now I should note that ammonia does not have infinite solubility in water. There is a limit depending on temperature. At room temperature of 25 celsius the maximum concentration is 31% by mass. So size your reactions to produce around that much. I’m sizing mine a bit more as i don’t expect good yield anyway. For 600mL of household ammonia at 10% concentration there should be about 60g of ammonia. Anyway, I ran this for about three hours and then removed the receiver flask to check the yield. And it looks like we have some, about 15.1g worth from about 600mL of household ammonia. Combining this with the original mass of water at 109.7g, this corresponds to a concentration of 12% by mass. While not bad, to be honest though i was hoping for a lot more, like 25% so it can be used to make hydrazine. While we could probably generate more ammonia from a fresh solution and bring up the concentration higher, or simply use much less water in our receiver, recovering only 2.5g of ammonia for every 100mL of household ammonia solution is not at all efficient. The ammonia is just too soluble in the solution so to boil it out is difficult at the already low concentrations present in household ammonia solutions. Nonetheless if this is all you have access to then there may not be another choice. If you make ammonia this way then I recommend using less water in your receiver so you get higher concentrations. But let’s try another approach. This time we’re going to react ammonium nitrate and sodium hydroxide. Ammonium nitrate is available in instant cold packs and sodium hydroxide is available as drain opener. This reaction has been used before to make sodium nitrate and the ammonia produced is usually lost in the fume hood as no attempt to recover it is made. But we’re going to try and recover it here by using a generator apparatus. Once again we measure receiver flasks before and after we add water so we know the mass. Then we prepare the sodium hydroxide solution by first getting 150mL of water and adding 120g of sodium hydroxide. This is done slowly as the heat produced can actually boil the solution. While that’s happening, in a separate container we mix 240g of ammonium nitrate with 160mL of water. Now we setup our apparatus which consists of vacuum flask containing our sodium hydroxide solution and connected on top is our addition funnel containing our ammonium nitrate solution. This in turn has a tube leading any gases produced into the receiver flask which is submerged in ice water this time for better recovery. Now we drip the ammonium nitrate solution into the sodium hydroxide solution and heat them up to drive out the ammonia. What’s happening is the sodium hydroxide is reacting with the ammonia nitrate to produce sodium nitrate and ammonia. I’ve set the reaction quantities to try and produce 51g of ammonia. But i only expect about half to be recovered. Oh you might be wondering why this lab is completely different from the earlier lab, this is because this video is pasted together from clips many years apart as I moved through different labs. I never quite had enough video to make a full video so I just sat on everything until now. Also, as we are about to see, this method sucked so there was no point to posting it on it’s own. What happened was after the solutions were mixed and heated for 3 hours I removed the receiver to measure the yield and only got about 2.7g of ammonia. This is pathetic. I think the primary reason is just the fact that in order to dissolve all the chemicals, a lot of water is needed. There is so much water that it dissolves the ammonia too well and thus very little can be boiled out. The logical answer is to use less water or even no water. The sodium hydroxide and ammonia nitrate will actually react with catalytic amounts of water. I choose not to pursue this method as the ammonia release is uncontrollable and not my objective if i want to carefully feed it into an ostwald reactor. The final method that worked very well was to use urea rather than ammonium nitrate. Once again we weigh the receiver flask. And in our generator flask we mix 200mL of water, 90g of urea, which is available as fertilizer as well as instant cold packs, and 120g of sodium hydroxide. The good thing about this mixture is that it’s stable enough that it won’t produce much ammonia until you start heating it. Once again i’ve set the quantity to produce 51g of ammonia. Now we setup our reflux condenser on top of the generator and once again lead the output to the receiver. We slowly heat the mixture until it starts to reflux. What’s happening is the urea is reacting with the sodium hydroxide to produce sodium carbonate and ammonia. The sodium carbonate will actually start precipitating out as it runs. I ran this for about three hours as well and then removed the receiver to measure the yield. The recovered yield of ammonia is 36.8g, very good actually as i was only expecting about 25g. When combined with the mass of water this comes out to a concentration of 26.9% This is viable for making hydrazine. Also this method is very well controlled, an important consideration if i want to feed this into making nitric acid by the ostwald process. I think the yield is so high because the sodium carbonate produced earlier is strongly alkaline, and this forces out the alkaline ammonia gas. I didn’t add more strong base to the ammonium nitrate method because i didn’t want to contaminate the very valuable sodium nitrate produced. I should go back and try to add sodium hydroxide to household ammonia method and see if that would improve the yield. Alternatively I should actually try and convert household ammonia into an ammonium salt, and then react it with a strong base at much higher concentrations. That should give much better yield. However just as i was planning to do this i lost my lab so that experiment will have to be put on hold. Nonetheless we did find a viable way to controllably produce useful amounts of ammonia and hopefully we can use this in the future projects. So that’s how you generate ammonia gas for amateur chemistry purposes. Thanks for watching Special thank you to all of my supporters on patreon for making these science videos possible with their donations and their direction. If you are not currently a patron, but like to support the continued production of science videos like this one, then check out my patreon page here or in the video description. I really appreciate any and all support.