Remember the coin experiment that I performed lately?
When I washed the coins, they looked different.
I finally figured out the answer.
Copper metal is oxidized by the Ag1+ to Cu2+ and the Ag1+ ions are reduced by the copper metal to silver metal.
But do you remember what the coins are made of?
Penny: The alloy remained 95 percent copper and 5 percent zinc until 1982, when the composition was changed to 97.5 percent zinc and 2.5 percent copper (copper-plated zinc) until now. Cents of both compositions appeared in that year.
50 Satang (Thai baht): The core is99% iron and cladding is 99% Copper.
10 Yen (Japanese Yen): 95% copper, 3–4% zinc, and 1–2% tin.
The Penny turned yellow-orange because the zinc was mixed with copper.
The Thai coin turned darker because of the iron.
The Japanese coin turned yellow because of the zinc and tin. Tin is light yellow and zinc is gray.
I hope you enjoyed that experiment, if you did, comment down below ↓
What about this experiment? Remember the silver tree? That was a great experiment. Go over there and check it out (here: https://danupondrake.wordpress.com/2017/06/25/the-silver-tree/). The silver nitrate will stick to the copper coil and make crystals. But instead of copper coils, why don’t we try copper coins? It will be fun to try! Let’s get started then!
Let’s some coins from different countries.
Penny (19 mm diameter): The alloy remained 95 percent copper and 5 percent zinc until 1982, when the composition was changed to 97.5 percent zinc and 2.5 percent copper (copper-plated zinc) until now. Cents of both compositions appeared in that year.
50 Satang (Thai baht) (18 mm diameter): The core is99% iron and cladding is 99% Copper.
10 Yen (Japanese Yen) (23.5 mm diameter): 95% copper, 3–4% zinc, and 1–2% tin.
To hang the coins in the beaker, I used paper clips to hold the coins…
…And tie rubber bands at each paper clips.
I made the solution for the experiment and dipped the coins in there…
Now I just have to wait.
30 Minutes later:
The coins are just turning blacker. So I took the coins out and cleaned them.
The coins look different. The penny turn yellow-orange, the Satang turned darker, and the Yen turned yellow.
But I wonder why…
Hope you enjoyed this post, if you did, tell me in the comment section ↓
As said on my post (it finally came 2) the silver nitrate is only 10 grams and it’s about $20. 10 grams is a little amount and it is very expensive, so I hope I don’t make any mistakes. The classic silver tree demonstration! Very simple to set up and perform, it’s great to introduce kids to the world of chemistry.
Things you’ll need: copper wire, silver nitrate, a beaker, and distilled water.
Pour 120 ml of distilled water into the beaker.
Pour about 4 grams of silver nitrate into the beaker.
Make a copper coil by wrapping copper wire around something round and taking it out. Put the copper coil into the beaker.
As you could see the reaction has started.
The more silver nitrate you add, the quicker the reaction starts.
Silver Crystals are covering the copper. It looks very pretty.
Prettiest experiment I ever performed.
This experiment is very easy to setup and very fun for kids.
You can keep going, but the more you wait, the more crystals will grow and turn blacker because when silver nitrate absorbs light, it will turn black. Now the silver nitrate is turning into silver metal.
Now I’m going to filter the silver metal out and see what comes out.
I got the silver metal. I put it in a bottle to preserve it.
The silver nitrate is in solution and the metallic copper will dissolve to form copper nitrate; as it does so, the silver in solution will be precipitated out as metallic silver. That is, the silver in solution is exchanged for copper and the copper that is not in solution is substituted for silver. Hope this makes sense!