The problem of definition is far from idle. It will hardly be pleasant if in a jewelry store instead of an expensive gold thing they want to slip an outright fake on you. Isn't it of interest what kind of metal a broken car part or a found antiquity is made of?
Instructions
Step 1
Here, for example, is how the presence of copper in an alloy is determined. Apply a drop of nitric acid solution (1: 1) to the cleaned metal surface. As a result of the reaction, gas will begin to evolve. After a few seconds, blot the drop with filter paper, then hold it over the flask where the concentrated ammonia solution is. The copper will react by dyeing the stain a deep blue.
Step 2
Here's how to distinguish bronze from brass. Place a piece of metal shavings or sawdust in a beaker with 10 ml of a solution (1: 1) of nitric acid and cover it with a glass. Wait a little for the metal to completely dissolve, and then heat the resulting liquid to an almost boil for 10-12 minutes. A white precipitate will remind you of bronze, and a beaker with brass will remain transparent.
Step 3
You can identify nickel in much the same way as copper. Apply a drop of nitric acid solution (1: 1) to the metal surface and wait 10-15 seconds. Blot the drop with filter paper and then hold it over concentrated ammonia vapor. On the resulting dark blue spot, drop a 1% solution of dimethylglyoxin in alcohol.
Step 4
Nickel will "signal" you with its characteristic red color. Lead can be determined using chromic acid crystals and a droplet of cooled acetic acid deposited on it, and a minute later - a drop of water. If you see a yellow precipitate, know that it is lead chromate.
Step 5
In order not to confuse gold, for example, with brass, apply a solution of nitric acid (1: 1) to the surface. If there is no reaction, consider yourself lucky - the gold content in the alloy exceeds 25%.
Step 6
Determining the presence of iron is also easy. Take a piece of metal and heat it in hydrochloric acid. If the result is positive, the contents of the flask should turn yellow. If you are at odds with chemistry, take a regular magnet. Be aware that all ferrous alloys are attracted to it.
