How to Gold Plate Metal with 24k Gold
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Although all that glitters may not be gold, it remains one of the most beautiful elements in its pure form. Gold was one of the first metals known to man. Gold cups and jewelry have been discovered in Iraq that predate 3500B .C. In the early 1900's, gold was a valued commodity as it was accepted by many countries as a formal currency. Its properties of malleability, resistance to tarnish, and high conductivity (not to mention its lust), made it the ideal metal for jewelers and electronic designers- as well an attractive scientific experiment for people to trying and synthesize the valuable metal from other compounds.
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It was once believed that gold could be synthesized out of a close relative on the periodic table: lead. However, it was John Dalton who discovered in the early 1900's that all matter is made up of tiny particles called atoms which cannot be dived (or added) to form new elements and cannot be destroyed, making it impossible to create gold from another element.
He was correct, mostly. Atoms do make up a fundamental element, however his rules against division and addition of protons was proven to be wrong. In the late 1930’s, Hans Bethe in collaboration with Peierls won a Nobel prize for their discovery that the fusion of hydrogen nuclei formed deuterium which created an energy generating mechanism utilized by stars as described with Einstein's relation between energy and mass: E=mc². It was many years after, scientists discovered it was possible to inject lead with a proton to create the next massive element, gold. However, the process requires an enormous amount of energy to create just one atom of gold, making it incredibly expensive and time-consuming. But the quest to create gold products did not end there.
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Although the dream of synthesizing gold has been put on the back burner, scientists reverted back to an 1800's method attaching gold onto metallic surfaces. An Italian chemist, Luigi Brugnatelli, discovered a method of how to electroplate gold onto other surfaces back in the 1800's by a method using a voltaic pile (basically a sandwiched pair of two metals interleaved by a moist conductor that when a current passes through, the metals became chemically bound).
40 years later, another chemist by the name of John Wright of Birmingham, in England discovered that potassium cyanide readily dissolved gold into an aqueous solution. When a current passes through an electrolyte and into the solution, a flow of ions is stimulated which created the necessary flow of ions to run an otherwise non-spontaneous reaction.
The method involves dissolving the gold, setting up a battery with the positive end connected to a solid piece of gold, and the negative end connected to the metallic object to be electroplated (you can see the process below in the diagram for silver which functions the exact same way as gold). The gold cyanide drops out of solution and because it is now charged, it becomes attracted to the oppositely charged object, creating a thin plating of gold creating the appearance of a solid piece of gold when the actual value is less than US$20! The gold can be recycled out of old computer chips or can be purchased at any bank. Check out below for the full process on how to electroplate metals with gold
[Image Source: UC DAVIS CHEMWIKI]