Making Silver Nitrate from Silver Metal

Making Silver Nitrate from Silver Metal


Today we’re making some silver nitrate
which is a salt of silver metal. Silver nitrate has historically been used as an antiseptic and it has a few uses in chemistry. I don’t have any plans to use it in a
synthesis reaction but I do want to carry out some demonstrations. I want to
finally get around to doing the silver mirror experiment and I also want to mix
it with some magnesium to make a water sensitive explosive. I do already have a
video where I demonstrate the mixture of magnesium and silver nitrate, but I
really want to revisit it. In general the process to make silver nitrate is pretty simple. The first thing we do is react silver
medal with nitric acid to make a solution of silver nitrate. The water is
removed by evaporation and this leaves behind our silver nitrate. In terms of chemicals all we need for
this preparation is silver metal and some concentrated nitric acid. Both of
the silver pieces that you see here weigh about 31.25 grams which is a little bit
above a troy ounce. For the nitric acid I found a decent amount to use was a little bit more than a milliliter per gram of silver. So to react the 60 2.5
grams of silver I used about sixty five milliliters of the nitric acid. To start things off I put the two pieces of
silver into a beaker. Onto the silver I then added about sixty
five milliliters of concentrated nitric acid. The silver loses its luster almost
immediately after adding the nitric acid. As we let the nitric acid sit with the
silver it will take on a yellow color but not much else will happen. To get the reaction going we’re going to
have to heat things up a little bit using a hot plate. It’s important not to heat things up too
quickly because we don’t the reaction to be too violent. What we really want to do is add enough
heat for the reaction to get going on its own and once it started it will
generate its own heat and keep itself going. As we continue to heat things the color
will transition from a yellow to an orange and eventually to a near red. The overall reaction is shown here where
silver is reacting with nitric acid to form silver nitrate, nitrogen dioxide gas
and water. The nitrogen dioxide gas is what gives
the solution its color and the more nitrogen dioxide we produce, the darker
the solution is going to get. As the reaction starts to pick up we’ll
have a lot of bubbles coming off the silver metal and will start to release
some nitrogen dioxide fumes. The fumes will get thicker and thicker
and eventually the reaction will take off. Once the reaction really got going I
turned off the hot plate to prevent it from getting out of control. Nitrogen dioxide gas in general is
dangerous to breathe so it’s very important to do this in a
well-ventilated area. As the silver continues to react will be
building up some silver nitrate and it’s important to occasionally stir things.
I’m not exactly sure why but initially it seems like the silver nitrate has a
hard time dissolving. I think we might just be producing
silver nitrate faster than it can dissolve into the water but i’m not
exactly sure. When most of the silver is reacted the
reaction will start to die down and we’ll start to dissolve some of the
silver nitrate precipitate we see here. The reaction now is much less vigorous
but we’re still just going to leave things until most of the silver has
dissolved. As we get closer to the end the solution
becomes more colorless and the color of the nitrogen dioxide gas starts to fade. The most annoying part is when we’re
very close to the end and we have just some small pieces of silver left that
seem to be taking forever to fully react. Because most of the nitric acid has
reacted its concentration of solution is quite low and the reaction rate is
pretty slow. In theory we could just leave things and let it react but I was
a little bit impatient so I added some more nitric acid. Not too long after adding the nitric
acid all of the silver is reacted and now we let things cool down. As we let things cool down the
solubility of silver nitrate in solution will decrease and eventually silver
nitrate crystals should come out. Sometimes it happens though that we get
a supersaturated solution and even when it’s cooled down no crystals come out. To get the solution to crystallize I’m
going to need to provide a seed crystal. There were some crystals that formed on
the watch glass so I knocked these in and you can see immediately crystals
start to form. Once it looks like the crystallization
is complete the solution is placed into a freezer. When the beakers tilted on the
side you can see all of the ice crystals that are formed. The first thing I did was dumped out any
excess liquid. I then place the beaker on the side let
more liquid pool at the bottom and then I dump that out as well. When it seems like most of the water had
been poured off I used the glass rod to break up the crystals. The crystals were then dumped out into a
glass bowl. After I dumped out all of the crystals I
looked at the beaker and it seemed like there was still quite a bit left over. To
wash the beaker I use the water that we had decanted out earlier. Now we have a nice liquid mixture of
silver nitrate in water and we have to evaporate off the water. My workspace is air-conditioned so the
water came off quite quickly. During this drying process it’s pretty important to keep the silver nitrate in the dark because it does degrade when exposed to light. After just a few days I was left with
some superdry silver nitrate crystals. I crush the crystals into a powder using
the bottom of a beaker and then I transferred them to a container for
storage. As I said before the silver nitrate is
sensitive to light so I covered it with aluminum foil
prevented from degrading. The final yield of silver nitrate was 96 grams which corresponds to a percent yield of about ninety-eight percent. These
types of reactions where we just reactive metal with an acid, usually have
yields around a hundred so this isn’t too spectacular. Anyway now that I have
96 grams of silver nitrate this is much more than I need. Like I said before I want to use it to
do the silver mirror experiment and to make the water sensitive explosive with
magnesium, but I’m not exactly sure what I’m going to do this. As usual I’d like to extend a big thanks
to all my supporters on Patreon and especially those who donate five dollars
or more. Anyone who donates and supports my Patreon gets to see my videos 24
hours before I release it to YouTube and if you donate five dollars more, you get
your name at the end of the video, like you see here. In the next few months
though I want to work on my Patreon page lot and I want to get more rewards going
and maybe even get some higher tier ones and I want to also offer some Patreon
exclusive content, also as usual here’s the videos that I’ve currently filmed
and the ones that plan to work on, if you have any suggestions or ideas, please
feel free to leave them in the comments

100 Comments

  1. I'm trying to isolate elemental boron from Borax powder, but I'm running into a couple practical problems along the way. I would LOVE to see you do this procedure on your channel, NileRed. I'm sure you could do it more efficiently and less wastefully than I, and it'd be super helpful for me and others to watch. I'm sure you can find the procedure on your own, but I'll outline it basically anyway. If you even happen to see this, that is.

    1. Borax + HCL = boric acid
    2. Heat boric acid at 300 degrees C to produce boron trioxide
    3. Thermite with magnesium to produce some boron, some magnesium boride, and some magnesium oxide
    4. Dissolve products in HCl, which will dissolve everything except elemental boron

  2. Hey Nile (or any of you guys watching), got a question: Is crystallization temperature dependant or vice versa? What I mean is, do things (yogurt in this case) crystallize because they are cold, or they become cold, because they have crystallized? I noticed my yougurt had cristalized in the freezer, but the center was still at normal temperature, even with the spoon in the center of it. Then the question popped. Did the yogurt's temperature drop, because the yogurt crystallized, or did the yogurt crystallize because the freezer's temperature dropped? Is it easier to drop a material's temperature, if it is in a solid state? My brain is frozen. I'm not that good at chemistry, but I love it anyways!!!

  3. Where do you get all of your glass bottles, plastic bottles and things??! They're awesome! I need some, and old pill bottles aren't cutting it.

  4. Hey Nile! Is it cheaper to buy it rather than to make it? Which compound will it decompose into over time? AgOH(s) or silver oxide? + Ag(s)?

  5. Shouldn't the reaction start faster when adding a bit of water? At the very beginning it's rather obvious that a nitrate has a hard time dissolving into nitric acid.
    But I'm guessing you didn't want to have more water than really needed.

  6. Where do you purchase the bulk of your reagents from? I'm trying to start a home lab and I would love to know where I can get some inexpensive lab grade chemicals to use.

  7. Hey! great gob, as usual !
    I have an idea of new synthesis for you : geraniol. It smells considerably, is a repellant against mosquitoes and the formula seems not too long to synthesise it

  8. The silver nitrate is not dissolving cause of two identical anions(NO3- of the silver nitrate and No3- of the nitric acic) "fighting for solvation". As you used conc. nitric acid there are a lot of the NO3- in solution wich causes a decreased solubility of silver nitrate but as the reaction is continuing the concentration of No3- is kept at one level by immediately dissolving silver nitrate and the exess is percipitating out. In the end everything dissolves cause the solution is pretty hot and the HNO3 was used up.

    I have not done any caculations on this yet to verify!

  9. Totally unrelated question about your "how to extract limonene from orange peels" video.
    Could you add that to actual food without it hurting you?
    Love your channel btw.

  10. Nile, could you put the product in a desiccator to dry it? I know this is not the main objective of a desiccator, but would it somehow damage the silica? And if it's okay, why don't you do that?

  11. Your one of my inspirations Nile. I'm 13 and I'm a home chemists so generally people don't understand what I talk about when in conversation about this topic, so when people like you who have the courage to make a YouTube channel like this post excellent content like you do it really is what teaches me things. I have learnt more from YouTube in the past year about chemistry then I have in school. Keep up the good work.

  12. It's kinda sketch and I certainly wouldn't make a video about it, but if you want to mess with explosives erythritol tetranitrate is a relatively simple and stable chemical that you could easily synthesize

  13. I've noticed that you'll be making the classic blue bottle reaction. Have you tried using benzoin as a reducing agent instead of glucose. It works quite well under alkaline conditions and you don't need that much as well. Furthermore, other redox indicators can also be used to obtain a different colour changing effect. Will try to show you some examples. TERRIFIC WORK! KEEP IT UP!

  14. Nile red is it possible for you to make KMnO4 from KOH , MnO2 and KNO3 and then converting the K2MnO4 to KMnO4 by passing Chlorine gas through the K2MnO4 solution? I saw it on a sciencemadness thread and it does not produce MnO2 when converting K2MnO4 to KMnO4, I am curious to see the result

  15. Hey NileRed, I have a video suggestion for you: an informative behind-the-scenes explanation of how you do what you do.
    Could you please have a general walkthrough of your lab/workspace and your equipment? I'd like to know what kinds of equipment you've acquired, and how you got them. What would be the minimal setup needed to really be able to do some experimentation, how much would it cost, and where would one get these things? What are the resources that you use–are there any online forums for other garage chemists like yourself? How did you get started in the first place? Do you worry about the police coming after you? What are your safety procedures? How do you do your filming and editing?
    I think that this kind of video would give a lot of helpful perspective on how you do your amazing work, and would really help others start doing some chemistry on their own.

  16. hey nile red,
    could you make thioacetone? it is said to be the stinkiest compound known, and i know you like really smelly compounds.

  17. I'll be doing this soon, but I have to find some silver that I won't miss.
    Hey, try using a welding mask filter over your camera when you revisit the Mg/AgNO3 video so we can see what it looks like without the flash.

  18. I think that crystals formed in the beginning could be silver nitrite, then slowly reacting with nitric acid to produce nitrate (and more NO2). Just guessing.

  19. Silver nitrate is VERY useful for creating mirrors, I use it extensively for repairing old mirrors inside of antique cameras such as Leicas and Rolleiflexes since otherwise the glass would need to be given an aluminum vacuum deposition treatment which is way beyond the means of most private individuals. Mirror making shouldn't be considered criminal or suspicious!

  20. The silver nitrate is less soluble at the beginning, because of to the nitric acid, which increases the concentration of nitrate ions and causes more silver nitrate to precipitate. This is due to the solubility product.

  21. You can try to nucleate silver nanoparticles in within a solution of PVP & Etilenglicol adding some of the silver nitrate. more interesting if you have access to a SEM or a TEM

  22. Do not use a beaker,use a flask and a tube to conduct nitrogen oxides in another flask filled with water so you will get nitric acid back

  23. I have another question that is non related. I have a saltwater reef tank and 1 of the chemicals I dose to the tank is high purity calcium chloride in solid form that I mix with deionized water to create a diluted mixture that is added to the tank. but for some reason when I added the calcium chloride to the container with water there was an exothermic reaction that freaked me out lol do you happen to know what would have caused this ?

  24. i kept asking adults how do you make a mirror? ….ya paint it, i dunno ! silver nitrate i found out later educate your'eself !

  25. is it possible to go directly to silver nitrate from potassium nitrate without the intermediate nitric acid step?

  26. Okay but your yield on the nitrate was <50%. Wouldn't it have been better to bubble the NO2 through water to reclaim the HNO3? This would also make it safer and less polluting.

  27. out of curiosity, are you supposed to do something about NO2 gas in terms of waste disposal? or is it okay to let it out into the world?

  28. Hey! Here's a way to reduce fuming in your lab!
    I ran this reaction in a Flat Bottom flask with an adapter for tubing which lead to a beaker of water. I put a pasture pipette on the end of the tubing so that the bubbling would occur more frequently at lower volume. I neutralized the waste with potassium hydroxide and threw in aqueous waste.
    Hope someone finds this comment helpful!

  29. I'm a photographer specialized in wet plate photography process, so I use lots of AgNO3. Thank you for the video, I might attempted to try it out myself. My suggestion to additionally purify the solution by sunning it. Yes, that's how 19th Century photographers were doing it and it works. You may check my video, but since I don't want to paste the direct link, since it could be recognised as spamming, I invite you to google: How to boil silver-nitrate bath for wet plate collodion process.
    Thank you again and topshit happens!

  30. Could you do a nitroethane synthesis video I'm having a hard time recreating this nitroethane synthesis and I need this for a few experiments that I'm trying

  31. extract dmt bro you should make a video with your incredible ability to detail the steps and dangers about making a successful extraction like you usually do

  32. Hi I have some silver and I wanted to make colloidal silver but I am looking into alternative methods of making some kind of silver carbonate that would be safe to ingest kind of like lithium carbonate I have not came across any videos how to make silver carbonate is it not possible to make?

  33. The silver nitrate probably isn't dissolving due to the common Ion effect, too much NO3- because of the concentrated acid.

  34. Is it because the concentration of (Conc) HNO3 is 70% at best?
    That way you would need roughly 90ml of acid to dissolve 62.5g of silver?
    Forgive me if this is wrong or has already been said.
    Find your videos really interesting though.
    Could you do one on the thermal decomposition of Silver Nitrate?

  35. Years late to this video…
    The fuming white of your "conc" nitric acid suggest its that 98% pure stuff and not the azeotropic kind (I know if I understood the jargon better this sentence is unnecessary). I think the driving mechanism in the whole reaction is your water balance. The reaction starts very slowly until there is enough water to start properly carrying the acid, The silver nitrate doesn't dissolve until there is enough water its not competing with the acid. I suspect you could do this without heating by simply adding water or using less concentrated acid.

    But What do I know I am a drunk keyboard warrior…

  36. silver nitrate based cream saved me from skin grafts after an explosion where lost most of the skin from my face and hands. goes on white and turns black over time in an endothermic reaction which is quite soothing on a burn

  37. I love your channel. just recently found it and watched almost all your vids now. I've used thiosulphate for cold plating for a scenic painting process. no idea how it works, but it's supposed to be safe for old silverware. is true?

  38. I love your channel. This experiment reminded me of that time in school when I started studying chemistry for the first time in my life, and in the first class the teacher asked us to investigate about a simple experiment and recreate it in front of the class. With the help of an uncle that was an engineer, I could make this cool and simple experiment where you dissolve a stick of silver nitrate in distilled water and then put a copper bar in the solution. Small silver crystals will start to form in the surface of the copper bar, while the bottom of the container starts getting blue because of the copper nitrate formed. I think it was quite cool.

  39. The reason the solid silver nitrate initially builds up, is because its solubility in concentrated nitric acid is actually very low. As the nitric acid is used up and decomposed later in the stage, the solubility of the silver nitrate increases.
    For this reason I have also found that you can speed up the reaction if you dilute the nitric acid, initially. This does however require that you supply continuous heat all the way through the dissolution.

Leave a Reply

Your email address will not be published.


*