Sodium Metal vs Silver Nitrate

Sodium Metal vs Silver Nitrate


[opening music] Hi everyone, welcome back to Cody’s Lab. So here is a glass of water, and here is a piece of sodium metal. Now you probably all know what happens when sodium metal reacts with water, but just as a refresher, here we go: You see, there is quite a vigorous reaction taking place here. What’s happening is that the sodium metal is so reactive, it’s able to replace hydrogen in the water molecule, forming sodium hydroxide and releasing the hydrogen gas. It also releases lots of heat. Now that the sodium is used up, I now have a solution of sodium hydroxide in water. Now I have over here another beaker which contains silver nitrate. In fact, this is a concentrated solution which contains as much silver nitrate as I could get to dissolve at this temperature. Now if we pour a little bit of the silver nitrate into the sodium hydroxide solution, we should see a dark black or brown precipitant. So there we go. Now what this is, is silver oxide being produced. Now, the silver is very unreactive, it wants to be as close to its elemental state as possible, and silver nitrate is not an elemental state. But sodium is happy to have this nitrate ion, so sodium goes on and makes a sodium nitrate, and the silver reacts and forms silver hydroxide. Now, the silver hydroxide is also reacted with water, so it immediately forms silver oxide. I’ll put all the reactions somewhere on screen. So, now we have a solution with silver oxide. But, this begs the question, what happens if I put the sodium into the silver nitrate directly? So, let’s try this and find out. Here’s a nice shiny piece of sodium metal, there’s my silver nitrate solution, let’s drop it in and see what happens. Okay… nothing seems to happen at first… I do see a little bit of a black silver oxide forming… so I imagine that’s because the sodium is reacting with water forming so- sodium hydroxide- ooh! That was unexpected! That ignited! That was a very vigorous reaction, actually! That was interesting! Did not expect that. So let’s see what we got. Hold this up, look inside of there, there’s some reactions going, so there was a little bit of sodium metal still… there’s definitely some hard white material in there. Let me get a piece of that out and have a look at it. So I just pulled some of the material out of the flask, so this dark, brownish black stuff, that’s pretty obviously silver oxide, but this hard, white material, right there? which was what was coating the sodium metal, was a bit more of a mystery to me. But after looking at it a little bit closer I’ve determined that it is actually silver nitrate. So what I think’s happening here, is the sodium is pulling the water out of the silver nitrate solution, leaving behind silver nitrate salt, which is hot enough that it melts. And when it solidifies it forms a nice hard white material. But while it’s molten, silver nitrate will react with sodium metal, similar to how potassium nitrate will react with sugar. So we’re actually burning the sodium metal. That reaction should form silver metal, sodium oxide (which then will react with water), and nitrogen gas. So to see if any silver metal is actually formed, I’ve now poured off all the silver nitrate solution, leaving the black sludge at the bottom, and now I’m going to add some ammonia. Now, this is ammonium hydroxide, and that should be able to dissolve the silver oxide, but it won’t dissolve silver metal. So if we’re left with silver metal, it should be rather obvious. So I have now obtained a mostly clear solution, let’s bring this over to the light so we can see it better, so there’s definitely some material down at the bottom still, in fact, look at this, I’d say there’s actually some little beads of silver metal! So we did form silver. How bout’ that! So let’s pull one of those out there so you can see it better. So there it is, a little bead of silver metal. It’s about a… millimetre wide or so? Yup, we did form silver! So that was a fun little experiment, hope y’all enjoyed, I’ll see you next time. [ending music]

100 Comments

  1. Could you possibly do a video about making graphene / graphene sheets? I've been so interested in this material and I've been wondering how I could make it at my house, and if there were any way to make is transparent?

  2. Anybody else not pay attention at all in chemistry and you've been watching all of cody's videos not knowing at all what's going on?

  3. Could you blow up a rock of at least 1m3 with black powder? To show how it was at the beginning of mining. I searched for a video about this and did not find it. Sorry for bad english, I'm latin american

  4. Cody, i remember a while ago you posted a video of you drinking water with dry ice in it. I have just watched grant thompsons video and he said that if you put dry ice into liquid nitrogen then the dry ice will become as cold as liquid nitrogen. Would you still be willing to drink the water with dry ice at liquid nitrogen temperatures? Thanks

  5. Hey Cody, I don't know if you have the equipment and know-how to do this, but I would be very interested in seeing you manufacture a high chromium content pocket knife forged by yourself. I know you need some very high temperatures and a good eye and hammer to forge a high quality knife…either a throwing knife or a special pocket knife. Perhaps a knife of a special alloy forged at home? Do you have the equipment for this, and if you do, do you know how to do it? I think it would be absolutely badass if you made a forged high quality blade! Thanks in advance for your response!

  6. Always burn the hydrogen, because the Earth loses 70 tons of hydrogen per year, because it is the lighter gas and easily escapes our atmosphere, see these small details when you are studying for the Mars One and help our planet

  7. Hey Cody, Its winter and I have been using those hand warmer packets and I looked at the ingredients of them and they have iron, so I was wondering if you could possible retrieve the iron fron the packets, it would be interesting.

  8. Yay Ive been subscribed to you for about a year and this is probobly my favourite Video! I love the ones with the reactions involved because it goes good in what I am learning in chemistry class. Your channel is one of the main things that had sparked my love for chemistry. I hope you get 1 million subs soon! Because you sure do deserve it

  9. Cody, I really can't believe you were surprised when the sodium ignited on contact with an aqueous solution. I'm no chemist, but even I would have expected that. You just said it for better audience involvement, didn't you? 😉

  10. My idiot lab partner spilled AgNO3 on my hand during a lab and I've got a black stain on most of my palm that won't go away. It'll probably be there for a few weeks.

  11. someone mentioned to me that apparently a certain toilet cleaner and tin foil react violently together, maybe a suggestion for a future video, I was curious just what chemical it would be reacting to.

  12. sometimes when you talk about a video you made years back i remember seeing it when you first posted it like it was a couple months ago, this channel ages VERY well and it seems you always come up with fresh new interesting ideas while looping back to other topics you've done in the past. LOVE IT

  13. Hi Cody — you should check out the old physics videos of "Julius Sumner Miller", who gave really good physics tutorials with an awesome sense of style. All on youtube. "Julius Sumner Miller". Just thought you'd appreciate his style (and hair).

  14. Interesting that Sodium reacts a lot slower with the saturated solution of AgNO₃. I expected that the NO₃¯ would react even stronger with the Na than the water alone. Is that due to the saturated solution that has to be broken up first? How does Na react with a saturated solution of NaCl or NaHCO₃?

  15. How about adding sodium to molten silver nitrate (anhydrous)?

    While you've got the molten silver nitrate, dip a thin wooden splint into it. It should burn slowly up the wood, but the "ash" will be mostly silver metal, with all the physical details (wood grain, etc) of the original splint.

  16. @Cody'sLab Can you recommend a chemistry book that would cover all the basics and could be used as a reference if the internet wasn't available? A "chemistry bible"?

  17. Why didn't you add some sodium hydroxide or a bit of sodium metal to the silver oxide dissolved with ammonium hydroxide to form fulminating silver (Ag3N)? It is a very, very shock sensitive explosive that will detonate even under water. It is an interesting experiment, but I recommend doing it with caution and in small amounts. You can make a little in a test tube and then drop this tube as it is, with water, to see how sensitive it is.

  18. It is likely worth noting that the addition of ammonium to silver oxide in the presence of nitrate, as you have done, forms "Tollen's reagent", which while useful becomes extremely dangerous as it ages. This mixture should not be stored and should be treated with dilute acid to destroy it.

  19. How do I educate myself in chemistry if I do not have chemistry as a subject in my university program and all the experience in learning before was horrible? Internet is an answer but a very unspecified one. So far I do understand about atom structure, electron energy level counts and stability, but there are so so much little things in chemistry which are a complete blank for me, I did not manage to find a good online education source. One of my first questions would probably be: How do you even tell apart wether the product of a chemical reaction will be a solid, liquid or gas?

  20. I made silver nitrate by reacting silver bullion (1g) with some 2.0M Nitric Acid solution. I also made sodium hydroxide solution using sodium hydroxide and water. When I mix the two together, I don't get a silver oxide precipitate. Why would this be? Is it becuase I used nitric acid solution because in the UK we can't get neat nitric acid we can only get solutions of it.

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